问题 填空题

改正下列错误的说法.

(1)加热氧化汞生成汞和氧气,氧化汞中含有氧气分子.改正为______.

(2)氢气在氧气中燃烧生成水,水中含有氢分子和氧分子.改正为:______.

(3)含氧的化合物都是氧化物.改正为:______.

(4)碳和氧气反应后,生成了二氧化碳,所以说二氧化碳是由碳和氧气构成的.改正为:______.

答案

(1)从宏观上看,物质是由元素组成的;因此氧化汞中含有氧气分子,应改为:氧化汞中含有氧元素;

故答案为:氧化汞中含有氧元素;

(2)从宏观上看,物质是由元素组成的;因此水中含有氢分子和氧分子,应改为:水中含有氢元素和氧元素;

故答案为;水中含有氢元素和氧元素;

(3)根据氧化物是指由两种元素组成且其中一种是氧元素的化合物,因此含氧的化合物都是氧化物.应改为:含氧的化合物不一定是氧化物,如氯酸钾;

故答案为:含氧的化合物不一定是氧化物;

(4)从微观上看物质是由分子或原子构成的;因此二氧化碳是由碳和氧气构成的,应改为:二氧化碳是由二氧化碳分子构成;  故答案为:二氧化碳是由二氧化碳分子构成.

单项选择题
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.\