[单项选择]Scientists say that many factors ______ changes in the weather.
A. bring in
B. bring off
C. bring about
D. bring forward

[单项选择]Scientists say that many factors ______ changes in the weather.
A. bring in
B. bring off
C. bring about
D. bring forward

[单项选择]Scientists say that many factors ______ great changes in the weather.
A. brought about
B. brought on
C. brought up
D. brought forward

[单项选择]With lasers scientists can probe many physical processes, such as combustion, once beyond our ken.
A. understanding
B. responsibility
C. interpretation
D. notice

[单项选择]Scientists employ many modern techniques to ______ the origin of the world.
A. watch
B. grasp
C. treat
D. probe

[单项选择]Why scientists say no to GM cotton
A. Because the cotton was genetically modified.
B. Because the cotton was found to damage the environment.
C. Because the cotton harms the bollworm.
D. Because Monsanto dismissed the research.

[单项选择]What do scientists say about the violent coming course of an asteroid with the earth

[单项选择]

Scientists say they now have proof to support the old-fashioned advice that it’s best to sleep on a problem. They say sleep strengthens the memory and helps the brain organize the masses of information we receive each day. Lead researcher Bob Stickgold at the Harvard Medical School said, "Sleep helps us draw rules from our experiences. It’s like knowing the difference between dogs and cats. even if it’s hard to explain. " The US research team studied how well students remembered connections between words and symbols (象征) , reports New Scientist. They compared how the students performed if they had had a sleep between seeing the words and having the test, and if they had not slept. They found that people were better able to remember lists of related words after a night’ s sleep than after the same time spent awake during the day. They also found it easier to remember themes (主题) that the words had in common. But they forgot around one in four more
A. pay full attention to a problem
B. wait until later for a decision
C. sleep to forget a problem
D. have difficulty sleeping

[单项选择]What do scientists say about the collision of an asteroid with Earth

[单项选择]Why do many scientists think animals are basically sleepwalkers
A. Because animals learn to carry out complex actions.
B. Because animals are trained to carry out complex actions.
C. Because animals carry out complex actions in response to stimuli.
D. Because animals carry out complex actions without awareness.

[单项选择]Not surprisingly, many scientists predict that such changes in the climate will probably result in hotter days.
A. 毫不奇怪，许多科学家都预计气候的这些变化可能会导致天气变暖。
B. 毫不奇怪，许多科学家认为这样的变化可能会导致热天更多。
C. 许多科学家对于气候变化和炎热天气所产生的后果毫不惊讶。
D. 许多科学家都认为天气变暖会改变气候，这并不令人怀疑。

[单项选择]Scientists say it may be five or six years （） this medicine is tested on human beings.
A. since
B. before
C. after
D. when

[单项选择]Many scientists are so convinced of the benefits of challenging the brain that they are putting it into practice in their lives.
A. 许多科学家都确信，在他们的生活中，经常练习挑战大脑，就会带来效益。
B. 许多科学家都对勤于动脑的益处确信不移，他们在自己的生活中也努力实践着。
C. 许多科学家都如此确信挑战大脑会带来利益，他们的实际生活证实了这一点。
D. 许多科学家都相信，他们生命中所实践的就是对人的大脑挑战，这种挑战是有益的。

[单项选择]Many scientists hold that global warming can be controlled by.