[单项选择]

Where Have All the Frogs Gone

 

In the 1980s, scientists around the world began to notice something strange: Frogs were disappearing. More recent research has shown that many kinds of amphibians (两栖动物) are declining or have become extinct. They have been around for a long time—over 350 million years. Why are they dying out now
Scientists are seriously concerned about this question. First of all, amphibians are an important source of scientific and medical knowledge. By studying amphibians, scientists have learned about new substances that could be very useful for treating human diseases. Further research could lead to many more discoveries, but that will be impossible if the amphibians disappear.
The most serious aspect of amphibian loss, however, goes beyond the amphibians themselves. Scientists are beginning to think about what amphibian decline means for the planet as a whole. If the
A. in any stream they can find
B. in places without UV light
C. only on sand
D. only in the right conditions

[单项选择]

 

In the 1980s, scientists around the world began to notice something strange: Frogs were disappearing. More recent research has shown that many kinds of amphibians (两栖动物) are declining or have become extinct. They have been around for a long time—over 350 million years. Why are they dying out now
Scientists are seriously concerned about this question. First of all, amphibians are an important source of scientific and medical knowledge. By studying amphibians, scientists have learned about new substances that could be very useful for treating human diseases. Further research could lead to many more discoveries, but that will be impossible if the amphibians disappear.
The most serious aspect of amphibian loss, however, goes beyond the amphibians themselves. Scientists are beginning to think about what amphibian decline means for the planet as a whole. If the earth is
A. it has been threatened by frogs
B. it is losing its habitat
C. a disease has been killing its eggs
D. it can’t bear the cold of winter

[单项选择]

In the 1980s, scientists around the world began to notice something strange: Frogs were disappearing. More recent research has shown that many kinds of amphibians (两栖动物) are declining or have become extinct. They have been around for a long time—over 350 million years. Why are they dying out now
Scientists are seriously concerned about this question. First of all, amphibians are an important source of scientific and medical knowledge. By studying amphibians, scientists have learned about new substances that could be very useful for treating human diseases. Further research could lead to many more discoveries, but that will be impossible if the amphibians disappear.
The most serious aspect of amphibian loss, however, goes beyond the amphibians themselves. Scientists are beginning to think about what amphibian decline means for the planet as a whole. If the earth is becoming u
A. knowledge about fatal human diseases
B. knowledge about air and water pollution
C. a chance to discover new medicines
D. an opportunity to detect poisonous gases

[单项选择]

Where Have All the Frogs Gone
In the 1980s, scientists around the world began to notice something strange: Frogs were disappearing. More recent research has shown that many kinds of amphibians (两栖动物) are declining or have become extinct. They have been around for a long time - over 350 million years. Why are they dying out now
Scientists are seriously concerned about this question. First of all, amphibians are an important source of scientific and medical knowledge. By studying amphibians, scientists have learned about new substances that could be very useful for treating human diseases. Further research could lead to many more discoveries, but that will be impossible if the amphibians disappear.
The most serious aspect of amphibian loss, however, goes beyond the amphibians themselves. Scientists are beginning to think about what amphibian decline means for the planet as a whole. If the earth is becoming unlivable for amphibians, is it also becoming
A. knowledge about fatal human diseases.
B. knowledge about air and water pollution.
C. a chance to discover new medicines.
D. an opportunity to detect poisonous gases.

[单项选择]We can all name slang expressions that have gone out of date, for instance, "right on" and "groovy" were popular in our parents" generation.
A. comma splice
B. correct
C. choppy
D. run on

[单项选择]He is not in the office. He must have gone to have classes, ______
A. didn’t he
B. doesn’t he
C. mustn’t he
D. hasn’t he

[单项选择]Is the News Believable
Unless you have gone through the experience yourself, or watched a loved one’s struggle, you really have no idea just how desperate cancer can make you. You pray, you rage, you bargain with God, but most of all you clutch at any hope, no matter how remote, of a second chance at life.
For a few excited days last week, however, it seemed as if the whole world was a cancer patient and that all humankind had been granted a reprieve (痛苦减轻). Triggered by a front-page medical news story in the usually reserved New York Times, all anybody was talking about — on the radio, on television, on the Internet, in phone calls to friends and relatives — was the report that a combination of two new drugs could, as the Times put it, "cure cancer in two years."
In a matter of hours patients had jammed their doctors’ phone lines begging for a chance to test the miracle cancer cure. Cancer scientists raced to the phones to make sure everyone knew about their rese
A. reduce the size of all tumors.
B. prevent breast cancer.
C. cure various diseases.
D. prevent uterine cancer.