[单项选择]In the experiments, ______.


A. there was an increase in the human consumption of salt
B. salt -eaters have bad health conditions
C. the environment was strictly monitored
D. high -blood pressure was easier put under control

[单项选择]Experiments show that different temperatures have different _________ on human feelings.
A. results
B. troubles
C. endings
D. effects

[单项选择]What do experiments show about our memories


A. We are more likely to remember things we do than things we see.
B. People always remember pleasant things rather than unpleasant ones.
C. Our ability to remember something depends on our feelings when it happens.
D. We tend to have better long-term memories than short-term memories.

[单项选择]Experiments enable young scientists to judge accurately what must be accepted and what must be viewed with suspicion.
A. doubt
B. belief
C. curiosity
D. judgment

[单项选择]Numerous experiments have demonstrated that mass is ______ to energy.
A. convertible
B. exchangeable
C. transplantable
D. conceivable

[单项选择]Experiments in the photography of moving objects （） in both the united states and Europe before 1990.
A. have been conducting
B. were conducting
C. had been conducted
D. are conducted

[单项选择]In scores of experiments, scientists are changing the genetic endowments of plants and animals, and the results could______ a revolution in farm fields, feedlots and dairy barns.
A. Spawn
B. bring
C. instigate
D. plot

[单项选择]By conducting experiments on brave volunteers, Walter Reed was able to identify the particularkind of mosquito that carried yellow fever.


A. thin
B. hearty
C. curious
D. courageous

[单项选择]Dr. Tichauer started his experiments initially to __________.


A. improve efficiency
B. increase production
C. reduce work load
D. improve comfort

[单项选择]Experiments by scientists have shown that when people evaluate individuals on certain attributes,______.


A. they observe the principle that beauty is only skin-deep
B. they do not usually act according to the views they support
C. they give ordinary-looking persons the lowest rating
D. they tend to base their judgment on the individual’s accomplishment

[单项选择]With the success of experiments on vaccine against some forms of cancer, the research group has been ______ itself up for the furtherance of research in this field.


A. preparing
B. equipping
C. gearing
D. framing

[单项选择]The experiments in giving the virus to animals proved that this type of influenza was easy to catch ______.


A. and could possibly cause death
B. and had rather mild effects
C. but was not deadly
D. and did not have the usual signs

[单项选择]The aim of controlled scientific experiments is ______.
A. to explain why things happen
B. to explain how things happen
C. to describe self-evident principles
D. to support Aristotelian science

[单项选择]

Text 1
A classic series of experiments to determine the effects of overpopulation on communities of rats was conducted by a psychologist, John Calhoun. In each experiment, an equal number of male and female adult rats were placed in an enclosure. The rat populations were allowed to increase. Calhoun knew from experience approximately how many rats could live in the enclosures without experiencing stress due to over crowding. He allowed the population to increase to approximately twice this number. Then he stabilized the population by removing offspring that were not dependent on their mothers. At the end of the experiments, Calhoun was able to conclude that overcrowding causes a break down in the normal social relationships among rats, a kind of social disease. The rats in the experiments did not follow the same patterns of behavior as rats would in a community without overcrowding.
The females in the rat population were the most seriously affected by the h
A. Dominant males had adequate living space.
B. Dominant males were not as seriously affected by overcrowding as the other rats.
C. Dominant males attacked weaker rats.
D. The strongest males are always able to adapt to bad conditions.