正确答案: D

what

题目：39______.

解析：D

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举一反三的答案和解析：

[单选题]B

Spending two or three hours playing outdoors each day can reduce a child’s chance of becoming short-sighted, a research shows. It challenges (挑战) the belief that short- sightedness is caused by computer use, watching TV or reading in weak light. The Australian government researchers believe that sunlight is good for people’s eyes. They compared the vision(视力) and habits of 100 seven-year-old children in Singapore and Australia. In all, 30% of the Singaporean children were short-sighted--this rate(比率) was ten times higher than Australian children. Both groups spent a similar amount of time reading, watching television and playing computer games. However, the Australian children spent an average(平均) of two hours a day outdoors—90 minutes more than the Singaporean children. Professor(教授) Ian Morgan, from the Australian Research Council’s Vision Centre, said, “Humans are naturally long-sighted, but when people begin to go to school and spend little or no time outdoors, the number of short-sighted people gets larger. We’re also seeing more and more short-sighted children in cities all around the world—and the main reason may be that city children spend less time outdoors. “ Daylight can be hundreds of times brighter than indoor light. But why does playing outside prevent us from becoming short-sighted? Scientists believe that natural light has a special chemical(化学物质) which stops the eyeball from growing out of shape and prevents people becoming short-sighted. So be outdoors. It doesn’t matter if that time is spent having a picnic or playing sports. 24. How much time did the Singaporean children spend outdoors on average every day in the research?

30 minutes.

[单选题]12．

one place

[单选题]13．

useful

[单选题]8．—How about _________ charity show?—I should say it was _________ success．

the ;a

解析：8．A【解析】句意：——慈善义演进行得怎样？一一应该说很成功。在说话双方都知道的名词前通常用定冠词 the; success作“成功者，成功的事”讲时是可数名词，故前面加不定冠词a。

[单选题]下列说法错误的是（ ）

氮气化学性质稳定，不能与其他任何物质反应

[单选题]．压瘪的乒乓球放入热水中重新鼓起，是因为球内的气体分子

间隔增大

[单选题]依次填入下面文段横线上的一组短语，恰当的一项是金都旅行社十分注重企业文化建设，始终坚持以 ___________ 、___________ 、___________ 、___________ 为奋斗目标，积极营造具有“金都”特色的企业文化氛围，打造“金都旅游，伴您畅游”企业服务品牌，取得显著的成效。

建一流企业 创一流业绩 塑一流员工 树一流形象

解析：D（注意把握四个短语中“建”“创”“塑”“树”这几个动词与宾语的搭配）

[单选题]AAgroupoffrogsweretravelingthroughtheforests,butunluckilytwoofthemfellintoahole.Theotherfrogstriedtohelp

deep