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问题 选择题

关于弹力，下列叙述正确的是（   ）

A．两物体相互接触，就一定会产生相互作用的弹力

B．两物体不接触，就一定没有相互作用的弹力

C．两物体有弹力作用，物体不一定发生了弹性形变

D．只有弹簧才能产生弹力

答案

答案：B

物体相互接触并发生弹性形变时才能产生弹力.故A错B对.有弹力一定发生了弹性形变，故C错.除弹簧外，其他物体也可能产生弹力，故D错.

单项选择题 A1/A2型题

下列哪项不是引起咳嗽的原因（）

A.咽喉炎

B.食管静脉曲张破裂出血

C.二尖瓣狭窄致肺水肿

D.支气管内膜结核

E.中枢性因素
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填空题

Exercising to music pumps up brain power


If music makes you smarter, and exercise helps brain function, can exercising to music really boost brainpower Some researchers said it can. Volunteers who listened to Vivaldi’s "Four Seasons" while working out on a treadmill did much better on a test of (1) ability than when they exercised without music, a team (2) Ohio State University found.
"Evidence suggests that exercise improves the (3) performance of people with coronary artery (4) ," said psychologist Charles Emery, who led the study.
"And listening to music is (5) to enhance brainpower. We wanted to put the two results together," Emery (6) in a statement.
Writing in the latest issue of the journal Heart & Lung, Emery and (7) said they studied 33 men and women taking (8) in a cardiac rehabilitation program after having bypass (9) , angioplasty or other procedures to treat clogged arteries.
The (10) said they felt better emotionally and mentally after working out (11) or without the music. But their improvement on the (12) fluency test doubled after listening to music on the treadmills.
"Exercise seems to (13) positive changes in the nervous system, and these changes may have a (14) effect on cognitive ability," Emery said.
"Listening to music may (15) cognitive function through different pathways in the brain. The combination of music (16) exercise may stimulate and increase cognitive arousal (17) helping to organize cognitive output."
Emery said he now wanted to (18) people using music of their own choice. "We used the ’Four Seasons’ because of its (19) tempo and positive effects on medical patients in previous (20) ," Emery said. "But given the range of music preferences among patients, it’s especially important to evaluate the influence of other types of music on cognitive outcomes.\
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