更多“23. How many hours of sleep is good for students' health?A. Less than 9 hours. B. Over ”相关问题
  • 第1题:

    有如下类定义: class Point{ private: static int how_many; }; ___________how_many=0; 要初始化Point类的静态成员how_many,下画线处应填入的内容是( )。

    A.int

    B.static int

    C.int Point::

    D.static int Point::


    正确答案:C
    本题考查静态数据成员,静态数据成员可以初始化,但只能在类体外进行初始化,其一般形式为:数据类型类名::静态数据成员名=初值。所以本题答案为C。

  • 第2题:

    9. He has a stomachache. He shouldn-t eat __________ for 24 hours.

    A. something

    B. everything

    C. anything

    D. nothing


    正确答案:C

  • 第3题:

    共用题干
    第三篇

    Judging from recent surveys,most experts in sleep behavior agree that it is virtually an epidemic of sleepiness in the nation."I can't think of a single study that hasn't found Americans getting less sleep than they ought to,"says Dr. David.Even people who think they are sleeping enough would probably be better off with more rest.
    The beginning of our sleep-deficit crisis can be traced to the invention of the light bulb a century ago.From diary entries and other personal accounts from the 18th and 19th centuries,sleep scientists have reached the conclusion that the average person used to sleep about 9.5 hours a night. "The best sleep habits once were forced on us,when we had nothing to do in the evening down on the farm,and it was dark." By the 1950s and 1960s,that sleep schedule had been reduced dramatically,to between 7.5 and 8 hours,and most people had to wake to an alarm clock."People cheat on their sleep,and they don't even realize they're doing it,"says Dr. David."They think they're okay because they can get by on 6.5 hours,when they really need 7.5,8 or even more to feel ideally vigorous."
    "Perhaps the most merciless robber of sleep,"researchers say,"is the complexity of the day." Whenever pressures from work,family,friends and community mount,many people consider sleep the least expensive item on his program."In our society,you're considered dynamic if you say you only need 5.5 hours' sleep.If you've got to get 8.5 hours,people think you lack drive and ambition."
    To determine the consequences of sleep deficit,researchers have put subjects through a set of psychological and performance tests requiring them,for instance,to add columns of numbers or recall a page read to them only minutes earlier."We've found that if you're in sleep deficit,performance suffers,"says Dr. David."Short-term memory is weakened,as are abilities to make decision and to concentrate."

    Many Americans believe that__________.
    A:sleep is the first thing that can be sacrificed when one is busy
    B:they need more sleep to cope with the complexities of everyday life
    C:to sleep is something one can do at any time of the day
    D:enough sleep promotes people's drive and ambition

    答案:A
    解析:
    细节题。答案相关句在第二段第三句:"The best sleep habits once were forced on us, when we had nothing to do in the evening down on the farm, and it was dark.”由此可知,以前夜晚一片漆黑,人们没有事做,因而那时的人们养成了最佳睡眠的习惯。本段首句提到了睡眠不足是因为电灯泡的发明,可推知十八九世纪的人因为没有照明,导致没有事情可做,因而养成了早睡觉的习惯。因此,选项B符合文意。选项A“没有精力和野心”和选项C “有最好的睡眠习惯”使用文中的只言片语进行干扰,不正确;选项D“第二天有很多事情要做”文中没有提及。
    推断题。在第二段后半部分中,大卫博士提到其实在睡眠上人们在自欺欺人,只是他们没有意识到而已,并且人们认为睡6.5个小时他们完全可以应付。事实上,要确保精力充沛,他们需要7.5个小时、8个小时或更长时间的睡眠。在第三段中,大卫博士指出,每当面对工作、家人、朋友和社会的巨大压力时,很多人认为睡眠是最不重要的,是最可以有弹性的。由此不难得出结论,美国人不在乎睡眠不足的后果或对此视而不见,因此选项B 符合文意。
    推断题。根据第三段内容可知,美国人往往通过减少睡眠时间的方式来处理生活中的事情,因为他们认为睡眠是最不重要的(the least expensive item)。因此,选项A 符合文意。选项B“需要更多的睡眠去应对生活压力”与文意正好相反;选项C“一天任何时候都可以用来睡觉”和选项D“充足的睡眠可以激发人的动力和野心”文中没有提及。
    语义题。由最后一段第一句的put subjects through...tests可知,这些subjects要经过一些测试,由此推知,subjects即 “测试对象”。因此,选项C为正确答案。
    推断题。由最后一段最后两句“We've found that if you're in sleep deficit, performance suffers…Short-term memory is weakened,as are abilities to make decision and to concentrate.”可知,睡眠关系到人的精力和表现,因此,选项D符合文意。虽然文章在最后一段提到了睡眠不足时,瞬时记忆力会下降,但并没有说睡多了可以提高记忆力,因此选项A“大幅度提高记忆力”不正确;选项B“被其他人认为精力充沛”是对原文的曲解;选项C“维持某人的日程安排”文中并未提及。

  • 第4题:

    Examine the following options, Multicasting supports applications that communicate.()

    A. many - to - one

    B. one - to - one

    C. one - to - many

    D. many - to - many


    参考答案:C

  • 第5题:

    共用题干
    第三篇

    Judging from recent surveys,most experts in sleep behavior agree that it is virtually an epidemic of sleepiness in the nation."I can't think of a single study that hasn't found Americans getting less sleep than they ought to,"says Dr. David.Even people who think they are sleeping enough would probably be better off with more rest.
    The beginning of our sleep-deficit crisis can be traced to the invention of the light bulb a century ago.From diary entries and other personal accounts from the 18th and 19th centuries,sleep scientists have reached the conclusion that the average person used to sleep about 9.5 hours a night. "The best sleep habits once were forced on us,when we had nothing to do in the evening down on the farm,and it was dark." By the 1950s and 1960s,that sleep schedule had been reduced dramatically,to between 7.5 and 8 hours,and most people had to wake to an alarm clock."People cheat on their sleep,and they don't even realize they're doing it,"says Dr. David."They think they're okay because they can get by on 6.5 hours,when they really need 7.5,8 or even more to feel ideally vigorous."
    "Perhaps the most merciless robber of sleep,"researchers say,"is the complexity of the day." Whenever pressures from work,family,friends and community mount,many people consider sleep the least expensive item on his program."In our society,you're considered dynamic if you say you only need 5.5 hours' sleep.If you've got to get 8.5 hours,people think you lack drive and ambition."
    To determine the consequences of sleep deficit,researchers have put subjects through a set of psychological and performance tests requiring them,for instance,to add columns of numbers or recall a page read to them only minutes earlier."We've found that if you're in sleep deficit,performance suffers,"says Dr. David."Short-term memory is weakened,as are abilities to make decision and to concentrate."

    According to Dr. David,Americans___________.
    A: are ideally vigorous even under the pressure of life
    B:often neglect the consequences of sleep deficit
    C:do not know how to relax themselves properly
    D:can get by on 6.5 hours of sleep

    答案:B
    解析:
    细节题。答案相关句在第二段第三句:"The best sleep habits once were forced on us, when we had nothing to do in the evening down on the farm, and it was dark.”由此可知,以前夜晚一片漆黑,人们没有事做,因而那时的人们养成了最佳睡眠的习惯。本段首句提到了睡眠不足是因为电灯泡的发明,可推知十八九世纪的人因为没有照明,导致没有事情可做,因而养成了早睡觉的习惯。因此,选项B符合文意。选项A“没有精力和野心”和选项C “有最好的睡眠习惯”使用文中的只言片语进行干扰,不正确;选项D“第二天有很多事情要做”文中没有提及。
    推断题。在第二段后半部分中,大卫博士提到其实在睡眠上人们在自欺欺人,只是他们没有意识到而已,并且人们认为睡6.5个小时他们完全可以应付。事实上,要确保精力充沛,他们需要7.5个小时、8个小时或更长时间的睡眠。在第三段中,大卫博士指出,每当面对工作、家人、朋友和社会的巨大压力时,很多人认为睡眠是最不重要的,是最可以有弹性的。由此不难得出结论,美国人不在乎睡眠不足的后果或对此视而不见,因此选项B 符合文意。
    推断题。根据第三段内容可知,美国人往往通过减少睡眠时间的方式来处理生活中的事情,因为他们认为睡眠是最不重要的(the least expensive item)。因此,选项A 符合文意。选项B“需要更多的睡眠去应对生活压力”与文意正好相反;选项C“一天任何时候都可以用来睡觉”和选项D“充足的睡眠可以激发人的动力和野心”文中没有提及。
    语义题。由最后一段第一句的put subjects through...tests可知,这些subjects要经过一些测试,由此推知,subjects即 “测试对象”。因此,选项C为正确答案。
    推断题。由最后一段最后两句“We've found that if you're in sleep deficit, performance suffers…Short-term memory is weakened,as are abilities to make decision and to concentrate.”可知,睡眠关系到人的精力和表现,因此,选项D符合文意。虽然文章在最后一段提到了睡眠不足时,瞬时记忆力会下降,但并没有说睡多了可以提高记忆力,因此选项A“大幅度提高记忆力”不正确;选项B“被其他人认为精力充沛”是对原文的曲解;选项C“维持某人的日程安排”文中并未提及。