单选题Bill can inspect a case of cell phones in 6 hours. Jack can inspect the same case of cell Phones in 4 hours. After working alone for l hour, Bill stops for lunch. After taking a 30-minute lunch break. Bill and Jack work together to inspect the remainin

题目
单选题
Bill can inspect a case of cell phones in 6 hours. Jack can inspect the same case of cell Phones in 4 hours. After working alone for l hour, Bill stops for lunch. After taking a 30-minute lunch break. Bill and Jack work together to inspect the remaining cell phones. How long do Bill and Jack work together to complete the job?
A

1 hr. and l2 min

B

1 hr. and 24 min

C

2 hrs

D

2 hrs and lo min

E

2 hrs and 20 min


相似考题
参考答案和解析
正确答案: B
解析:
If x represents the number of hours Bill and Jack work together, then the total number of Bill’s working hours is x+1. Bill’s rate of work is 1/6 of the job per hour, and the Jack’s rate of work is 1/4 of the job per hour. Hence, (x+1)/6+x/4=1. x=2.
更多“Bill can inspect a case of cell phones in 6 hours. Jack can”相关问题
  • 第1题:

    According to the passage, which of the following statements is TRUE?()

    A.After the cell-phone ban is ended, students can use their phones during class

    B.The cell-phone ban is equally enforced in all public schools

    C.A phone-storage industry has appeared outside the 88 metal-detector campuses


    答案:A

  • 第2题:

    共用题干
    第一篇

    Cell Phones: Hang Up or Keep Talking?

    Millions of people are using cell phones today.In many places it is actually considered unusual not to
    use one.In many countries,cell phones are very popular with young people.They find that the phones are
    more than a means of communication一having a mobile phone shows that they are cool and connected.
    The explosions around the world in mobile phone use make some health professionals worried.Some
    doctors are concerned that in the future many people may suffer health problems from the use of mobile
    phones.In England,there has been a serious debate about this issue.Mobile phone companies are worried
    about the negative publicity of such ideas.They say that there is no proof that mobile phones are bad for your
    health.
    On the other hand,why do some medical studies show changes in the brain cells of some people who use
    mobile phones?Signs of change in the tissues of the brain and head can be detected with modern scanning
    (扫描)equipment. In one case , a traveling salesman had to, retire at a young age because of serious memory
    loss.He couldn't remember even simple tasks.He would often forget the name of his own son.This man
    used to talk on his mobile phone for about six hours a day,every day of his working week,for a couple of
    years.His family doctor blamed his mobile phone use,but his employer's doctor didn't agree.
    What is it that makes mobile phones potentially harmful?The answer is radiation.High-tech machines
    can detect very small amounts of radiation from mobile phones.Mobile phone companies agree that there is
    some radiation,but they say the amount is too small to worry about.
    As the discussion about their safety continues,it appears that it's best to use mobile phones less often.
    Use your regular phone if you want to talk for a long time.Use your mobile phone only when you really need
    it. Mobile phones can be very useful and convenient,especially in emergencies.In the future,mobile phones
    may have a warning label that says they are bad for your health.So for now,it's wise not to use your mobile
    phone too often.

    People buy cell phones for the following reasons EXCEPT that_______________.
    A:they're popular
    B:they're useful
    C:they're convenient
    D:they're cheap

    答案:D
    解析:
    由第一段可知,人们买手机是因为它流行,从最后一段第四句可知,买手机是因为它方便又实用。
    detect意思为“发现,找到”,discover的意思与之一样。
    由第三段的第三、四句话可知,这个商人很年轻就退休是因为他丧失了记忆力,连简单 的任务都记不住了。
    由第四段的最后一句话可知,手机公司认为手机的辐射很小,不足以对人们的健康造 成伤害。
    由最后一段第一句话可知,作者的写作目的是劝我们最好少用手机。 第二篇 文章主要介绍了EoL这一工程的相关信息。

  • 第3题:

    共用题干
    第一篇

    Cell Phones: Hang Up or Keep Talking?

    Millions of people are using cell phones today.In many places it is actually considered unusual not to
    use one.In many countries,cell phones are very popular with young people.They find that the phones are
    more than a means of communication一having a mobile phone shows that they are cool and connected.
    The explosions around the world in mobile phone use make some health professionals worried.Some
    doctors are concerned that in the future many people may suffer health problems from the use of mobile
    phones.In England,there has been a serious debate about this issue.Mobile phone companies are worried
    about the negative publicity of such ideas.They say that there is no proof that mobile phones are bad for your
    health.
    On the other hand,why do some medical studies show changes in the brain cells of some people who use
    mobile phones?Signs of change in the tissues of the brain and head can be detected with modern scanning
    (扫描)equipment. In one case , a traveling salesman had to, retire at a young age because of serious memory
    loss.He couldn't remember even simple tasks.He would often forget the name of his own son.This man
    used to talk on his mobile phone for about six hours a day,every day of his working week,for a couple of
    years.His family doctor blamed his mobile phone use,but his employer's doctor didn't agree.
    What is it that makes mobile phones potentially harmful?The answer is radiation.High-tech machines
    can detect very small amounts of radiation from mobile phones.Mobile phone companies agree that there is
    some radiation,but they say the amount is too small to worry about.
    As the discussion about their safety continues,it appears that it's best to use mobile phones less often.
    Use your regular phone if you want to talk for a long time.Use your mobile phone only when you really need
    it. Mobile phones can be very useful and convenient,especially in emergencies.In the future,mobile phones
    may have a warning label that says they are bad for your health.So for now,it's wise not to use your mobile
    phone too often.

    On the safety issue of mobile phones,the manufacturing companies______________.
    A:deny the existence of mobile phone radiation
    B:develop new technology to reduce mobile phone radiation
    C:try to prove that mobile phones are not harmful to health
    D:hold that the amount of radiation is too small to worry about

    答案:D
    解析:
    由第一段可知,人们买手机是因为它流行,从最后一段第四句可知,买手机是因为它方便又实用。
    detect意思为“发现,找到”,discover的意思与之一样。
    由第三段的第三、四句话可知,这个商人很年轻就退休是因为他丧失了记忆力,连简单 的任务都记不住了。
    由第四段的最后一句话可知,手机公司认为手机的辐射很小,不足以对人们的健康造 成伤害。
    由最后一段第一句话可知,作者的写作目的是劝我们最好少用手机。 第二篇 文章主要介绍了EoL这一工程的相关信息。

  • 第4题:

    In a significant tightening of legal controls over the press,Lord Irvine,the Lord Chancellor,will introduce a( )bill that will propose making payments to witnesses illegal and will strictly control the amount of publicity that can be given to a case before a trial begins.

    A.sketch
    B.rough
    C.preliminary
    D.draft

    答案:D
    解析:
    A.sketch指“略图,草图;粗样;草稿;速写,素描”。B.rough指“粗糙的,表面不平的;粗暴的,粗鲁的,粗野的”;C.preliminary指“预备的;初步的;序言性的”;D.draft指“草稿,草案,草图”,draft bill(bill指由立法委员会提出的法律草案)是固定搭配。

  • 第5题:

    共用题干
    第二篇

    Cell Phones : Hang Up or Keep Talking?

    Millions of people are using cell phones today.In many places it is actually considered unusual not to
    use one.In many countries,cell phones are very popular with young people.They find that the phones are
    more than a means of communication一having a mobile phone shows that they are cool and connected.
    The explosions around the world in mobile phone use make some health professionals worried.Some
    doctors are concerned that in the future many people may suffer health problems from the use of mobile
    phones.In England,there has been a serious debate about this issue. Mobile phone companies are worried about
    the negative publicity of such ideas.They say that there is no proof that mobile phones are bad for your health.
    On the other hand,why do some medical studies show changes in the brain cells of some people who use
    mobile phones?Signs of change in the tissues of the brain and head can be detected with modern scanning
    equipment. In one case,a traveling salesman had to retire at a young age because of serious memory loss.He
    couldn't remember even simple tasks.He would often forget the name of his own son.This man used to talk
    on his mobile phone for about six hours a day,every day of his working week,for a couple of years. His family
    doctor blamed his mobile phone use,but his employer's doctor didn't agree.
    What is it that makes mobile phones potentially harmful?The answer is radiation.High-tech machines
    can detect very small amounts of radiation from mobile phones.Mobile phone companies agree that there is
    some radiation,but they say the amount is too small to worry about.
    As the discussion about their safety continues,it appears that it's best to use mobile phones less often.
    Use your regular phone if you want to talk for a long time.Use your mobile phone only when you really need
    it. Mobile phones can be very useful and convenient,especially in emergencies.In the future,mobile phones
    may have a warning label that says they are bad for your health.So for now,it's wise not to use your mobile
    phone too often.

    People buy cell phones for the following reasons EXCEPT that_________.
    A:they're popular
    B:they're useful
    C:they're cheap
    D:they're convenient

    答案:C
    解析:
    由第一段第三句“cell phones are very popular”可知A项正确。由最后一段第四句“very useful and convenient”可知,B、D两项正确。故选C。
    根据语境可知detect的意思是“发现,查明”。故选C。
    由第三段可知那位销售员是因为严重的记忆问题而退休的,他连简单的任务都记不 住,故选D。
    由第四段最后一句可知,移动公司承认手机有一些辐射,但他们认为辐射的量很小,无 需担心。
    由文章最后一句可知,作者建议大家尽量少使用手机。 第三篇 本篇文章讲述了对杭微生物的杭力应引起注意。

  • 第6题:

    Cell Phone Lets Your Secrets Out
      Your cell phone holds secrets about you.Besides the names and numbers that you've programmed into it, ______traces____(51) of your DNA linger (遗留) on thedevice according to a new study
      DNA is genetic (遗传的)material _____that_____ (52) appears in every cell. Like your fingerprint, yourDNA is _____unique______ (53) to you——unless you have an identical twin. Scientiststoday analyze DNA in blood, saliva (唾液), orhair left ____behind_______ (54) at the scene of a crime. The results oftenhelp detectives identify ____criminals______ (55) and their victims. Your cellphone can reveal more about you ____than_____ (56) you might think.
      Meghan J. McFadden, a scientist at McMasterUniversity in Hamilton, Ontario, heard about a crime in which the suspect bledonto a cell phone and later dropped the____device_____ (57). This made herwonder whether traces of DNA lingered on cell phones一evenwhen no blood was___involved_____(58). She and colleague Margaret Wallace ofthe City University of NewYork analyzed the flip-open phones(翻盖手机)of10 volunteers. They used swabs (药签) tocollect _____invisible___ (59) traces of the users from two parts of the phone:the outside, where the user ____holds_____(60) it, and the speaker which isplaced at the user's ear
      The scientists cleaned the phones using asolution made mostly__of____(61) alcohol. The aim of washing was to remove alldetectable traces of DNA. The owners got their phones back for another week.Then the researchers ___returned________ (62) the phones and cleaned each phoneonce more.
      The scientists discovered DNA that _____belonged______(63) to the phone's speaker on each of the phones. Better samples werecollected from the outside of each phone, but those swabs also picked up DNAthat belonged to other people who had apparently also ____handed______ (64) thephone
      Surprisingly, DNA showed up even in swabsthat were taken immediately after the phones were scrubbed. That suggests thatwashing won't remove all traces of ___evidence________ (65) from a criminal'sdevice. So cell phones can now be added to the list of clues that can clinch (确定)a crime-scene investigation.
    文章(41~55)

      A. name
      B.pictures
      C. shapes
      D. traces


    答案:D
    解析:

  • 第7题:

    共用题干
    第三篇

    Cell Phones: Hang Up or Keep Talking?

    Millions of people are using cell phones today.In many places it is actually considered unusual not to
    use one.In many countries,cell phones are very popular with young people.They find that the phones are
    more than a means of communication一having a mobile phone shows that they are cool and connected.
    The explosions around the world in mobile phone use make some health professionals worried.Some
    doctors are concerned that in the future many people may suffer health problems from the use of mobile
    phones.In England,there has been a serious debate about this issue. Mobile phone companies are worried about
    the negative publicity of such ideas. They say that there is no proof that mobile phones are bad for your health.
    On the other hand,why do some medical studies show changes in the brain cells of some people who use
    mobile phones?Signs of change in the tissues of the brain and head can be detected with modem scanning
    (扫描)equipment. In one case , a traveling salesman had to retire at a young age because of serious memory
    loss.He couldn't remember even simple tasks.He would often forget the name of his own son.This man used
    to talk on his mobile phone for about six hours a day,every day of his working week,for a couple of years.
    His family doctor blamed his mobile phone use,but his employer's doctor didn't agree.
    What is it that makes mobile phones potentially harmful?The answer is radiation.High-tech machines
    can detect very small amounts of radiation from mobile phones.Mobile phone companies agree that there is
    some radiation,but they say the amount is too small to worry about.
    As the discussion about their safety continues,it appears that it's best to use mobile phones less often.
    Use your regular phone if you want to talk for a long time.Use your mobile phone only when you really need
    it. Mobile phones can be very useful and convenient,especially in emergencies.In the future,mobile phones
    may have a warning label that says they are bad for your health.So for now,it's wise not to use your mobile
    phone too often.

    People buy cell phones for the following reasons EXCEPT that_________.
    A:they're popular
    B:they're cheap
    C:they're useful
    D:they're convenient

    答案:B
    解析:
    由第一段第三句“cell phones are very popular”可知A项正确。由最后一段第四句“very useful and convenient”可知,C、D两项正确。故选B。
    根据语境可知detect的意思是“发现,查明”。故选C。
    由第三段可知那位销售员是因为严重的记忆问题而退休的,他连简单的任务都记不 住,故选C。
    由第四段最后一句可知,移动公司承认手机有一些辐射,但他们认为辐射的量很小,无需担心。
    由文章最后一句可知,作者建议大家尽量少使用手机。

  • 第8题:

    共用题干
    Cell Phones

    I Believe it or not,cell phones have been around for over a quarter of a century.The first commercial
    cell phone systemfl was developed by the Japancoc in I 979.But cell phones have changed a lot
    since that
    time.The early cell phones were big and heavy but they have developed into small and light palm-sized mod-
    els.There have been huge (lcveloprnents in their functions,too;we have had call forwarding,text messaging,
    answering services and hands-free use for years,but now there are countless new facilities,su,ch as instant ac-
    cess to the Internet and receiving and sending photos.
    2 Cell phones have become very common in our lives;recent statistics suggest as many as one in three
    people cii the planet now have a cell phone,and most of them say they couldn't live without one.Cell phones
    are used in every area of our lives and have become a necessary tool,used for essential arrangements,social
    contact and business.They have made it easier to call for help on the highway.They have made it possible to
    keep in touch with people"on the move”一when people are traveling.
    3 Cell phones have made communication easier and have reduced the need for family arguments.We
    can use cell phones to let our family know we'11 be late or if there’。a sudden change of tian or an emergen-
    cy.Cell phones have eased the worries of millions of parents when their teenagers are out late,they can now
    contact their children at any time.
    4 This does not mean that cell phones are all good news.They have brought with them a number of
    new headaches for their owners;it costs a lot to replace stolen phones,something that is becoming a frequent
    occurrence,and have you ever seen such huge phone bills? More serious,however,is the potential health
    problem they bring:there are fears that radiation from the phones may cause brain tumor(肿瘤).This may be
    a time bomb waiting to happen to younger people who have grown up with cell phones that they simply can't
    live without!

    Paragraph 3________
    A:Cell Phones and the Family
    B:Commercial Cell Phone Systems
    C:Cell Phones in Everyday Life
    D:Cell Phones for Teenagers
    E:History of Cell Phones
    F:Problems with Cell Phones

    答案:A
    解析:
    第一段开篇就说从手机发明到现在已过去了四分之一多个世纪,又对比了手机早期和 近期在功能一上的不同,由此可知是在叙述手机的历史。
    第二段讲手机在人们的生活中十分常见,许多人离不开手机,手机用于各个场合,因而 意在说明手机存在于日常生活中。
    第三段列举了手机对于家人联系上的作用,有助于减少家庭的误会纠纷,有助于父母 联系孩子,因而讲的是手机同家庭的关系。
    最后一段第一句就说明了该段要讲的是手机带来的问题,段中虽举了青少年的例子,但 不局限于描写青少年,因此选F。
    根据第一段末尾可知答案。
    根据第二段第三行可知答案。
    根据第三段第二句可知答案。
    根据第四段第二句可知答案。第4部分;阅读理解第一篇 本文主要介绍了北极冰川融化的情况、原因和科学家们的担心。

  • 第9题:

    共用题干
    Cell Phones

    I Believe it or not,cell phones have been around for over a quarter of a century.The first commercial
    cell phone systemfl was developed by the Japancoc in I 979.But cell phones have changed a lot
    since that
    time.The early cell phones were big and heavy but they have developed into small and light palm-sized mod-
    els.There have been huge (lcveloprnents in their functions,too;we have had call forwarding,text messaging,
    answering services and hands-free use for years,but now there are countless new facilities,su,ch as instant ac-
    cess to the Internet and receiving and sending photos.
    2 Cell phones have become very common in our lives;recent statistics suggest as many as one in three
    people cii the planet now have a cell phone,and most of them say they couldn't live without one.Cell phones
    are used in every area of our lives and have become a necessary tool,used for essential arrangements,social
    contact and business.They have made it easier to call for help on the highway.They have made it possible to
    keep in touch with people"on the move”一when people are traveling.
    3 Cell phones have made communication easier and have reduced the need for family arguments.We
    can use cell phones to let our family know we'11 be late or if there’。a sudden change of tian or an emergen-
    cy.Cell phones have eased the worries of millions of parents when their teenagers are out late,they can now
    contact their children at any time.
    4 This does not mean that cell phones are all good news.They have brought with them a number of
    new headaches for their owners;it costs a lot to replace stolen phones,something that is becoming a frequent
    occurrence,and have you ever seen such huge phone bills? More serious,however,is the potential health
    problem they bring:there are fears that radiation from the phones may cause brain tumor(肿瘤).This may be
    a time bomb waiting to happen to younger people who have grown up with cell phones that they simply can't
    live without!

    We can use cell phones to communicate with others when we encounter__________.
    A:a necessity
    B:an emergency
    C:a number of new hcadaches
    D:family arguments
    F:big and light palm-sized models
    F:countless new facilities

    答案:B
    解析:
    第一段开篇就说从手机发明到现在已过去了四分之一多个世纪,又对比了手机早期和 近期在功能一上的不同,由此可知是在叙述手机的历史。
    第二段讲手机在人们的生活中十分常见,许多人离不开手机,手机用于各个场合,因而 意在说明手机存在于日常生活中。
    第三段列举了手机对于家人联系上的作用,有助于减少家庭的误会纠纷,有助于父母 联系孩子,因而讲的是手机同家庭的关系。
    最后一段第一句就说明了该段要讲的是手机带来的问题,段中虽举了青少年的例子,但 不局限于描写青少年,因此选F。
    根据第一段末尾可知答案。
    根据第二段第三行可知答案。
    根据第三段第二句可知答案。
    根据第四段第二句可知答案。第4部分;阅读理解第一篇 本文主要介绍了北极冰川融化的情况、原因和科学家们的担心。

  • 第10题:

    单选题
    —Who can reach the book on the top shelf?—Jack can. He is ______ boy of us all.
    A

    taller

    B

    a tall

    C

    the tallest


    正确答案: C
    解析:
    本题考查的是形容词最高级的用法。句意:——谁能够到架子顶部的书?——杰克,他是我们中最高的男孩。“of us all”是一个具体的范围。taller是普通的比较级,用在“than”引导的句子中。因此选C。

  • 第11题:

    单选题
    Bill can inspect a case of cell phones in 6 hours. Jack can inspect the same case of cell Phones in 4 hours. After working alone for l hour, Bill stops for lunch. After taking a 30-minute lunch break. Bill and Jack work together to inspect the remaining cell phones. How long do Bill and Jack work together to complete the job?
    A

    1 hr. and l2 min

    B

    1 hr. and 24 min

    C

    2 hrs

    D

    2 hrs and lo min

    E

    2 hrs and 20 min


    正确答案: E
    解析:
    If x represents the number of hours Bill and Jack work together, then the total number of Bill’s working hours is x+1. Bill’s rate of work is 1/6 of the job per hour, and the Jack’s rate of work is 1/4 of the job per hour. Hence, (x+1)/6+x/4=1. x=2.

  • 第12题:

    问答题
    Practice 1Directions: For this part, you are allowed 30 minutes to write an essay commenting on the remark “More and more teenagers use cell phones.” You can cite examples to illustrate your point. You should write at least 150 words but no more than 200 words.

    正确答案:
    【范文】
    My View on the Use of Cell Phone among Teenagers It is usual if you notice a teenager in a school uniform speaking through a cell phone on the street.
    It is very convenient to have a cell phone at hand. In the event of an emergency, they can call their parents or teachers or even the police for help by cell phone. They can send text messages to their classmates exchanging ideas or seeking assistance in their learning when they are away from one another. And their parents will not be very worried as it is rather easy for them to contact their children and check their whereabouts and what they are doing by cell phone.
    However, some teenagers might indulge themselves in showing how fashionable their cell phones are to their peers. Such behavior might prove contagious and soon other users will be tempted to pester their parents for a showier new model of cell phone. What is annoying to teachers is that the ringing of cell phones will easily disturb the class if some of the students forget to switch off their cell phones in class.
    In conclusion, parents should think twice before they buy a cell phone for their children at primary or secondary schools.
    解析: 暂无解析

  • 第13题:

    共用题干
    Cell Phone Lets Your Secret Out

    Your cell phone holds secrets about you.Besides the names and _____________(51)that you've pro-
    grammed into it,traces of your DNA linger on the device,according to a new study.
    DNA is genetic material that______________(52)in every cell.Like your fingerprint,your DNA is unique
    to you一 _____________(53)you have an identical twin.Scientists today routinely analyze DNA in blood,
    saliva,or hair left _____________(54)at the scene of a crime.The results often help detectives identify
    _____________(55)and their victims.Your cell phone can reveal more about you _____________(56)you might
    think.
    Meghan J.McFadden,a scientist at McMaster University in Hamilton,Ontario,heard about a crime in
    which the suspect bled onto a cell phone and later dropped the______________(57).This made her wonder
    whether traces of DNA lingered on cell phones even when no blood was involved.______________(58)she and
    colleague Margaret Wallace of the City University of New York analyzed the flip-open phones of 10 volun-
    teers.They used swabs to collect______________(59)traces of the users from two parts of the phone:the
    outside,where the user holds it,and the______________(60),which is placed at the user's ear.
    The scientists scrubbed the phones using a solution made mostly______________(61)alcohol.The aim of
    washing was to remove all detectable traces of DNA.The owners got their phones______________(62)for
    another week.Then the researchers collected the phones and repeated the swabbing of each phone once
    more.
    The scientists discovered DNA that _____________(63)to the phone's speaker on each of the phones.
    Better samples were collected from the outside of each phone,but those swabs also picked up DNA that be-
    longed to other people who had apparently also handled the phone.______________(64),DNA showed up even
    in swabs that were taken immediately after the phones were scrubbed.That suggests that washing won't remove
    all traces of evidence from a criminal's device.So cell phones can now be added to the
    ______________(65)of clues
    that can clinch a crime-scene investigation.

    _________(60)
    A:card
    B:keys
    C:screen
    D:speaker

    答案:D
    解析:
    人们通常在手机中储存人名和他们的电话号码。所以A是最佳选择。虽然手机中也 能储存音乐、电影和秘密信息,相比之下,不如A合理。
    这个句子的意思是:DNA是一种存在于每一个细胞中的基因物质。appeal呼吁,吸引, 上诉;appoint任命,指定;appear有,出现;apply申请,应用。只有C项符合语境,故选C。
    此句的意思是:如同指纹,你的DNA是独一无二的——除非你有一个与你完全相同的 孪生兄弟或姐妹。因此,此处必须选择unless,其他选择均不符合语境,也违背了有关DNA的基本常识。
    leave behind是固定搭配,意为“留下”。
    根据对上下文的理解可推知,研究结果是用来帮助侦探识别罪犯和受害人的。由空后 的their victims(他们的受害者)也可知答案。
    句子中的more提供了选择的线索,more…than的搭配最能表达该句的意思。
    定冠词the说明该选项所指内容在前文中已经提到,即cell phone。除了device(设备, 装置),其他选项均不能指代。ell phone。
    前后两个句子是因果关系,故选B。句子大意为:这使她思考微量DNA是否会停留在 手机上,所以,她与同事一起对10名志愿者的翻盖手机进行了分析研究。A、C、D三项表示的 都是转折关系。
    句子当中的traces指的是DNA traces,而DNA traces是肉眼看不到的,所以选择invisible。
    研究者从手机的两部分收集微量DNA:一是手机外壳,二是喇叭。speaker在此处意为 “喇叭”。
    be made of是固定搭配,意为“由……制成”。a solution made mostly of alcohol:一种主要 由酒精制成的溶液。
    根据对上下文的理解,应该选择back。本句意思为:手机拥有者拿回了手机,再使用一 个星期。
    该句要表达的意思应该是:科学家在每一个手机上发现了属于手机拥有者的DNA。 belong to是固定搭配,意思是“属于”。
    空后内容告诉我们手机经过擦洗后仍然有微量DNA出现。所以这里要用surpiisingly 这个副词,表示令人惊讶。
    根据对上下文的理解,应该选择list,其他三个选项与句子的意思不符。

  • 第14题:

    共用题干
    第一篇

    Cell Phones: Hang Up or Keep Talking?

    Millions of people are using cell phones today.In many places it is actually considered unusual not to
    use one.In many countries,cell phones are very popular with young people.They find that the phones are
    more than a means of communication一having a mobile phone shows that they are cool and connected.
    The explosions around the world in mobile phone use make some health professionals worried.Some
    doctors are concerned that in the future many people may suffer health problems from the use of mobile
    phones.In England,there has been a serious debate about this issue.Mobile phone companies are worried
    about the negative publicity of such ideas.They say that there is no proof that mobile phones are bad for your
    health.
    On the other hand,why do some medical studies show changes in the brain cells of some people who use
    mobile phones?Signs of change in the tissues of the brain and head can be detected with modern scanning
    (扫描)equipment. In one case , a traveling salesman had to, retire at a young age because of serious memory
    loss.He couldn't remember even simple tasks.He would often forget the name of his own son.This man
    used to talk on his mobile phone for about six hours a day,every day of his working week,for a couple of
    years.His family doctor blamed his mobile phone use,but his employer's doctor didn't agree.
    What is it that makes mobile phones potentially harmful?The answer is radiation.High-tech machines
    can detect very small amounts of radiation from mobile phones.Mobile phone companies agree that there is
    some radiation,but they say the amount is too small to worry about.
    As the discussion about their safety continues,it appears that it's best to use mobile phones less often.
    Use your regular phone if you want to talk for a long time.Use your mobile phone only when you really need
    it. Mobile phones can be very useful and convenient,especially in emergencies.In the future,mobile phones
    may have a warning label that says they are bad for your health.So for now,it's wise not to use your mobile
    phone too often.

    The word"detected"in Paragraph 3 could be best replaced by______________.
    A:cured
    B:removed
    C:caused
    D:discovered

    答案:D
    解析:
    由第一段可知,人们买手机是因为它流行,从最后一段第四句可知,买手机是因为它方便又实用。
    detect意思为“发现,找到”,discover的意思与之一样。
    由第三段的第三、四句话可知,这个商人很年轻就退休是因为他丧失了记忆力,连简单 的任务都记不住了。
    由第四段的最后一句话可知,手机公司认为手机的辐射很小,不足以对人们的健康造 成伤害。
    由最后一段第一句话可知,作者的写作目的是劝我们最好少用手机。 第二篇 文章主要介绍了EoL这一工程的相关信息。

  • 第15题:

    共用题干
    第一篇

    Cell Phones: Hang Up or Keep Talking?

    Millions of people are using cell phones today.In many places it is actually considered unusual not to
    use one.In many countries,cell phones are very popular with young people.They find that the phones are
    more than a means of communication一having a mobile phone shows that they are cool and connected.
    The explosions around the world in mobile phone use make some health professionals worried.Some
    doctors are concerned that in the future many people may suffer health problems from the use of mobile
    phones.In England,there has been a serious debate about this issue.Mobile phone companies are worried
    about the negative publicity of such ideas.They say that there is no proof that mobile phones are bad for your
    health.
    On the other hand,why do some medical studies show changes in the brain cells of some people who use
    mobile phones?Signs of change in the tissues of the brain and head can be detected with modern scanning
    (扫描)equipment. In one case , a traveling salesman had to, retire at a young age because of serious memory
    loss.He couldn't remember even simple tasks.He would often forget the name of his own son.This man
    used to talk on his mobile phone for about six hours a day,every day of his working week,for a couple of
    years.His family doctor blamed his mobile phone use,but his employer's doctor didn't agree.
    What is it that makes mobile phones potentially harmful?The answer is radiation.High-tech machines
    can detect very small amounts of radiation from mobile phones.Mobile phone companies agree that there is
    some radiation,but they say the amount is too small to worry about.
    As the discussion about their safety continues,it appears that it's best to use mobile phones less often.
    Use your regular phone if you want to talk for a long time.Use your mobile phone only when you really need
    it. Mobile phones can be very useful and convenient,especially in emergencies.In the future,mobile phones
    may have a warning label that says they are bad for your health.So for now,it's wise not to use your mobile
    phone too often.

    The salesman retired young because_______________.
    A:he disliked using mobile phones
    B:he couldn't remember simple tasks
    C:he was tired of talking on his mobile phone
    D:his employer's doctor persuaded him to

    答案:B
    解析:
    由第一段可知,人们买手机是因为它流行,从最后一段第四句可知,买手机是因为它方便又实用。
    detect意思为“发现,找到”,discover的意思与之一样。
    由第三段的第三、四句话可知,这个商人很年轻就退休是因为他丧失了记忆力,连简单 的任务都记不住了。
    由第四段的最后一句话可知,手机公司认为手机的辐射很小,不足以对人们的健康造 成伤害。
    由最后一段第一句话可知,作者的写作目的是劝我们最好少用手机。 第二篇 文章主要介绍了EoL这一工程的相关信息。

  • 第16题:

    共用题干
    第二篇

    Cell Phones : Hang Up or Keep Talking?

    Millions of people are using cell phones today.In many places it is actually considered unusual not to
    use one.In many countries,cell phones are very popular with young people.They find that the phones are
    more than a means of communication一having a mobile phone shows that they are cool and connected.
    The explosions around the world in mobile phone use make some health professionals worried.Some
    doctors are concerned that in the future many people may suffer health problems from the use of mobile
    phones.In England,there has been a serious debate about this issue. Mobile phone companies are worried about
    the negative publicity of such ideas.They say that there is no proof that mobile phones are bad for your health.
    On the other hand,why do some medical studies show changes in the brain cells of some people who use
    mobile phones?Signs of change in the tissues of the brain and head can be detected with modern scanning
    equipment. In one case,a traveling salesman had to retire at a young age because of serious memory loss.He
    couldn't remember even simple tasks.He would often forget the name of his own son.This man used to talk
    on his mobile phone for about six hours a day,every day of his working week,for a couple of years. His family
    doctor blamed his mobile phone use,but his employer's doctor didn't agree.
    What is it that makes mobile phones potentially harmful?The answer is radiation.High-tech machines
    can detect very small amounts of radiation from mobile phones.Mobile phone companies agree that there is
    some radiation,but they say the amount is too small to worry about.
    As the discussion about their safety continues,it appears that it's best to use mobile phones less often.
    Use your regular phone if you want to talk for a long time.Use your mobile phone only when you really need
    it. Mobile phones can be very useful and convenient,especially in emergencies.In the future,mobile phones
    may have a warning label that says they are bad for your health.So for now,it's wise not to use your mobile
    phone too often.

    The writer's purpose of writing this article is to advise people_________.
    A:to buy mobile phones
    B:to use mobile phones less often
    C:to update regular phones
    D:to stop using mobile phones

    答案:B
    解析:
    由第一段第三句“cell phones are very popular”可知A项正确。由最后一段第四句“very useful and convenient”可知,B、D两项正确。故选C。
    根据语境可知detect的意思是“发现,查明”。故选C。
    由第三段可知那位销售员是因为严重的记忆问题而退休的,他连简单的任务都记不 住,故选D。
    由第四段最后一句可知,移动公司承认手机有一些辐射,但他们认为辐射的量很小,无 需担心。
    由文章最后一句可知,作者建议大家尽量少使用手机。 第三篇 本篇文章讲述了对杭微生物的杭力应引起注意。

  • 第17题:

    It can not be used before ( ).
    A. inspect B. inspected
    C. being inspected D. inspecting


    答案:C
    解析:

  • 第18题:

    The mobility of cell phones means you can be anywhere and have the____or should I say the convenience, of a phone.

    A.must
    B.accompaniment
    C.conclusion
    D.necessity

    答案:D
    解析:
    本题考查词语意思。题目意为“手机的移动性意味着你可以在任何地方,并且具有必要性,或者我应该说,手机的方便性。”A项意为“绝对必要的事物”。B项意为“伴奏、伴随物”。C项意为“结论、论断”。D项意为“必需品,必要”。因此选D项,有必要。
      

  • 第19题:

    共用题干
    第二篇

    Cell Phones: Hang Up or Keep Talking?

    Millions of people are using cell phones today.In many places it is actually considered unusual not to
    use one.In many countries,cell phones are very popular with young people.They find that the phones are
    more than a means of communication一having a mobile phone shows that they are cool and connected.
    The explosions around the world in mobile phone use make some health professionals worried.Some
    doctors are concerned that in the future many people may suffer health problems from the use of mobile
    phones.In England,there has been a serious debate about this issue.Mobile phone companies are worried about
    the negative publicity of such ideas.They say that there is no proof that mobile phones are bad for your health.
    On the other hand,why do some medical studies show changes in the brain cells of some people who use
    mobile phones?Signs of change in the tissues of the brain and head can be detected with modern scanning
    equipment. In one case,a traveling salesman had to retire at a young age because of serious memory loss.He
    couldn't remember even simple tasks.He would often forget the name of his own son.This man used to talk
    on his mobile phone for about six hours a day,every day of his working week,for a couple of years. His family
    doctor blamed his mobile phone use,but his employer's doctor didn't agree.
    What is it that makes mobile phones potentially harmful?The answer is radiation.High-tech machines
    can detect very small amounts of radiation from mobile phones.Mobile phone companies agree that there is
    some radiation,but they say the amount is too small to worry about.
    As the discussion about their safety continues,it appears that it's best to use mobile phones less often.
    Use your regular phone if you want to talk for a long time.Use your mobile phone only when you really need
    it. Mobile phones can be very useful and convenient,especially in emergencies.In the future,mobile phones
    may have a warning label that says they are bad for your health.So for now,it's wise not to use your mobile
    phone too often.

    The writer's purpose of writing this article is to advise people___________.
    A:to buy mobile phones
    B:to stop using mobile phones
    C:to update regular phones
    D:to use mobile phones less often

    答案:D
    解析:
    由第一段第三句:"cell phones are very popular”可知C项正确。由最后一段第四句 "very useful and convenient”可知B、D两项正确。故选A。
    根据语境可知detect的意思是“发现,查明”。故选D。
    由第三段可知那位销售员是因为严重的记忆问题而退休的,他连简单的任务都记不 住,故选C。
    由第四段最后一句可知,移动公司承认手机有一些辐射,但他们认为辐射的量很小,无 需担心。
    由文章最后一句可知,作者建议大家尽量少用手机。 第三篇 本篇文章主要讲述了如何处理脚踩扭伤的问题。

  • 第20题:

    共用题干
    Cell Phones

    I Believe it or not,cell phones have been around for over a quarter of a century.The first commercial
    cell phone systemfl was developed by the Japancoc in I 979.But cell phones have changed a lot
    since that
    time.The early cell phones were big and heavy but they have developed into small and light palm-sized mod-
    els.There have been huge (lcveloprnents in their functions,too;we have had call forwarding,text messaging,
    answering services and hands-free use for years,but now there are countless new facilities,su,ch as instant ac-
    cess to the Internet and receiving and sending photos.
    2 Cell phones have become very common in our lives;recent statistics suggest as many as one in three
    people cii the planet now have a cell phone,and most of them say they couldn't live without one.Cell phones
    are used in every area of our lives and have become a necessary tool,used for essential arrangements,social
    contact and business.They have made it easier to call for help on the highway.They have made it possible to
    keep in touch with people"on the move”一when people are traveling.
    3 Cell phones have made communication easier and have reduced the need for family arguments.We
    can use cell phones to let our family know we'11 be late or if there’。a sudden change of tian or an emergen-
    cy.Cell phones have eased the worries of millions of parents when their teenagers are out late,they can now
    contact their children at any time.
    4 This does not mean that cell phones are all good news.They have brought with them a number of
    new headaches for their owners;it costs a lot to replace stolen phones,something that is becoming a frequent
    occurrence,and have you ever seen such huge phone bills? More serious,however,is the potential health
    problem they bring:there are fears that radiation from the phones may cause brain tumor(肿瘤).This may be
    a time bomb waiting to happen to younger people who have grown up with cell phones that they simply can't
    live without!

    Cell phones are common in our lives and have become_________.
    A:a necessity
    B:an emergency
    C:a number of new hcadaches
    D:family arguments
    F:big and light palm-sized models
    F:countless new facilities

    答案:A
    解析:
    第一段开篇就说从手机发明到现在已过去了四分之一多个世纪,又对比了手机早期和 近期在功能一上的不同,由此可知是在叙述手机的历史。
    第二段讲手机在人们的生活中十分常见,许多人离不开手机,手机用于各个场合,因而 意在说明手机存在于日常生活中。
    第三段列举了手机对于家人联系上的作用,有助于减少家庭的误会纠纷,有助于父母 联系孩子,因而讲的是手机同家庭的关系。
    最后一段第一句就说明了该段要讲的是手机带来的问题,段中虽举了青少年的例子,但 不局限于描写青少年,因此选F。
    根据第一段末尾可知答案。
    根据第二段第三行可知答案。
    根据第三段第二句可知答案。
    根据第四段第二句可知答案。第4部分;阅读理解第一篇 本文主要介绍了北极冰川融化的情况、原因和科学家们的担心。

  • 第21题:

    单选题
    It can be inferred that the attitude of the WHO and the British government toward the use of mobile phones is ______.
    A

    precautious

    B

    skeptical

    C

    approving


    正确答案: C
    解析:
    观点态度的找寻和判断。关于世界卫生组织和英国政府对使用移动电话的态度,录音中提到“世界卫生组织已经呼吁对手机的潜在健康威胁进行更多的研究,同时力劝人们减少手机的使用”。而英国政府的做法是“advised parents to discourage their children…from using them excessively”(建议家长劝阻他们的孩子过度使用手机)。由此可推测,世界卫生组织和英国政府对移动电话的使用持有谨慎的态度。precautious有戒备的,警惕的。因此A项为正确答案。

  • 第22题:

    单选题
    —Jack, ______ you ride a bike?—Yes, I can.
    A

    can

    B

    may

    C

    need

    D

    must


    正确答案: D
    解析:
    句意:—杰克,你会骑车吗?—是的,我会。本题考查情态动词的使用。can表能力。may表推测。need表“需要”。must意为“必须”,可以用来表示十分肯定的推测。A项符合句意。

  • 第23题:

    单选题
    According to the passage, which of the following statements is TRUE?
    A

    After the cell-phone ban is ended, students can use their phones during class.

    B

    The cell-phone ban is equally enforced in all public schools.

    C

    The cell-phone ban was put into place in 2008 under mayor Bill de Blasio.

    D

    A phone-storage industry has appeared outside the 88 metal-detector campuses.


    正确答案: B
    解析:
    根据第四段第二句“Ending the ban will also likely end an industry that has sprung up near…other devices for a dollar a day”可知,众多学校周边曾经兴起一桩生意:为青少年保存手机和其他设备,费用为一天一美元。又根据文中第三段第一句“But at the 88 city schools with metal detectors”可知是88所具有金属探测器的学校,因此可判断正确答案为D。根据文章最后一句话“It will include rules about not using the phones during class or to cheat on tests”可知,上课或考试时使用手机是不允许的,A项错误。根据文章首句“which is not equally enforced in all schools”可以判断,B项错误。根据文章第四段首句“The ban was put into place in 2007 under mayor Michael Bloomberg”可知,该禁令是2007年Michael Bloomberg实施的,因此可以判断C项错误。

  • 第24题:

    单选题
    Which of the following can Jack do?
    A

    He can take a No.19 bus to Geyuan Garden

    B

    He can visit the Slender West Lake at 8:00

    C

    He can call 0514 -87935285 for further information of Ho Family Garden

    D

    He can go to www. he-garden, net to know more about Ho Family Garden


    正确答案: B
    解析:
    由原文最后一段给出的网站“Website: http: //www. he-garden.Net”可知D项正确。原文第三段指出,No.8, 30, 61 buses可到Geyuan Garden,故A项错误。原文第二段提到瘦西湖的观赏时间是8:30—17:00,故B项错误。原文第三段中提到0514–87935285是Geyuan Garden的服务电话,而不是Ho Family Garden的电话,故C项也错误。因此应选D项。