寄生虫（parasite）

请阅读Passage l。完成第21—25小题。
Passage 1
It's one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse s brain.
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to"cure" mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women--it is linked to blindness and the death of unborn babies.
However, the parasite's effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine(尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell,which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans?
The answer lies in evolution.
"It's exciting scary to know how a parasite can manipulate a mouse's brain this way," Ingram said. But she also finds it inspiring."Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away."
She said, but this study has proven that wrong."This may have huge implications for infectious disease medicine."

Which of the following statements is true according to the passage?
查看材料

A．Toxoplasma gondii causes people strange and deadly diseases.
B．With certain infection the infectious disease cannot be cured completely.
C．Human beings infected by toxoplasma gondii will have permanent brain damage.
D．Toxoplasma gondii is harmful to human beings, but it does no harm to mice.

机会性致病寄生虫是指

A、兼性寄生虫
B、专性寄生虫
C、偶然寄生虫
D、免疫功能正常时致病的寄生虫
E、免疫功能异常时致病的寄生虫

It’s one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse’ s brain.
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to “cure” mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women—it is linked to blindness and the death of unborn babies.
However, the parasite’s effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine (尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell, which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans The answer lies in evolution.
“It’s exciting scary to know how a parasite can manipulate a mouse's brain this way,"Ingram said. But she also finds it inspiring. "Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away,” she said, but this study has proven that wrong. “This may have huge implications for infectious disease medicine."

Which of the following statements is true according to the passage 查看材料

A.Toxoplasma gondii causes people strange and deadly diseases.
B.With certain infection the infectious disease cannot be cured completely.
C.Human beings infected by toxoplasma gondii will have permanent brain damage.
D.Toxoplasma gondii is harmful to human beings, but it does no harm to mice.

It’s one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse’ s brain.
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to “cure” mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women—it is linked to blindness and the death of unborn babies.
However, the parasite’s effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine (尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell, which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans The answer lies in evolution.
“It’s exciting scary to know how a parasite can manipulate a mouse's brain this way,"Ingram said. But she also finds it inspiring. "Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away,” she said, but this study has proven that wrong. “This may have huge implications for infectious disease medicine."

The author's attitude towards the experiment is__________.查看材料

A.positive
B.subjective
C.negative
D.objective

机会致病寄生虫是

A:偶然感染的寄生虫
B:免疫功能低下时致病的寄生虫
C:暂时寄生的寄生虫
D:免疫功能正常时致病的寄生虫
E:随即感染的寄生虫

It’s one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse’ s brain.
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to “cure” mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women—it is linked to blindness and the death of unborn babies.
However, the parasite’s effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine (尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell, which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans The answer lies in evolution.
“It’s exciting scary to know how a parasite can manipulate a mouse's brain this way,"Ingram said. But she also finds it inspiring. "Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away,” she said, but this study has proven that wrong. “This may have huge implications for infectious disease medicine."

The passage is mainly about__________.查看材料

A.mice's inborn terror of cats
B.the evolution of Toxoplasma
C.a new study about the effects of a parasite on mice
D.a harmful parasite called Toxoplasma gondii

根据以下材料，回答
It′s one of our common beliefs that miceare afraid of cats. Scientists have long known that even if a mouse has neverseen a cat before, it is still able to detect chemical signals released from itand run away in fear. This has always been thought to be something that is hard-wiredinto a mouse′ s brain.
But now Wendy Ingram, a graduate student atthe University of California, Berkeley, has challenged this common sense. Shehas found a way to "cure" mice of their inborn fear of cats by infectingthem with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii,might sound unfamiliar to you, but the shocking fact is that up to one-third ofpeople around the world are infected by it. This parasite can cause different diseasesamong humans, especially pregnant women--it is linked to blindness and thedeath of unborn babies.
However, the parasite′s effects on mice areunique, Ingram and her team measured how mice reacted to a cat′ s urine (尿) before and after it was infected by the parasite. They noted thatnormal mice stayed far away from the urine while mice that were infected withthe parasite walked freely around the test area.
But that′s not all. The parasite was foundto be more powerful than originally thought--even after researchers cured themice of the infection. They no longer reacted with fear to a cat′s smell, whichcould indicate that the infection has caused a permanent change in mice′ sbrains.
Why does a parasite change a mouse′s braininstead of making it sick like it does to humans? The answer lies in evolution.
"It′s exciting scary to know how aparasite can manipulate a mouse′s brain this way," Ingram said. But shealso finds it inspiring. "Typically if you have a bacterial infection, you go to a doctor andtake antibiotics and the infection is cleared and you expect all the symptomsto also go away." She said, but this study has proven that wrong. "This may have huge implicationsfor infectious disease medicine."
The experiment found that mice infectedwith toxoplasma gondii ____________.

A.stayed far away from cat' s urine
B.moved around the area freely andfearlessly
C.because more sensitive to cat' s smell
D.were more afraid of cats

根据以下材料，回答
It′s one of our common beliefs that miceare afraid of cats. Scientists have long known that even if a mouse has neverseen a cat before, it is still able to detect chemical signals released from itand run away in fear. This has always been thought to be something that is hard-wiredinto a mouse′ s brain.
But now Wendy Ingram, a graduate student atthe University of California, Berkeley, has challenged this common sense. Shehas found a way to "cure" mice of their inborn fear of cats by infectingthem with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii,might sound unfamiliar to you, but the shocking fact is that up to one-third ofpeople around the world are infected by it. This parasite can cause different diseasesamong humans, especially pregnant women--it is linked to blindness and thedeath of unborn babies.
However, the parasite′s effects on mice areunique, Ingram and her team measured how mice reacted to a cat′ s urine (尿) before and after it was infected by the parasite. They noted thatnormal mice stayed far away from the urine while mice that were infected withthe parasite walked freely around the test area.
But that′s not all. The parasite was foundto be more powerful than originally thought--even after researchers cured themice of the infection. They no longer reacted with fear to a cat′s smell, whichcould indicate that the infection has caused a permanent change in mice′ sbrains.
Why does a parasite change a mouse′s braininstead of making it sick like it does to humans? The answer lies in evolution.
"It′s exciting scary to know how aparasite can manipulate a mouse′s brain this way," Ingram said. But shealso finds it inspiring. "Typically if you have a bacterial infection, you go to a doctor andtake antibiotics and the infection is cleared and you expect all the symptomsto also go away." She said, but this study has proven that wrong. "This may have huge implicationsfor infectious disease medicine."
The author′s attitude towards theexperiment is ____________.

A.positive
B.subjective
C.negative
D.objective