问题 单项选择题

关于绝热材料的绝热性能,以下哪个不正确().

A.材料中,固体物质的导热能力比空气小 

B.材料受潮后,导热系数增大 

C.对各向异性材料,平行热流方向热阻小 

D.材料的导热系数随温度升高而加大

答案

参考答案:A

解析:

一般情况下,固体物质的导热能力比空气大;材料受潮后,由于孔隙中水蒸气的扩散和液态水的热传导,热导率增大;环境温度升高时,由于材料固体分子的热运动增强,孔隙中空气的导热和孔壁间的辐射作用加强,热导率增大;对各向异性材料,平行热流方向热阻小。

完形填空

阅读下面短文,并根据短文后的要求答题(请注意问题后的字数要求)。

[l]Children learn by doing. While children may feel love towards others,they aren' t always sure how to express it. Parents can teach their children to love others by helping them find proper ways to express their care and concern. When they do so,their children will have a better understanding of what loving others really means.

[2]Provide Opportunities: Care and compassion are a part of love.Teach your child to love others by providing opportunities to put love into action. Make a card for a sick friend, bring cookies to an elderly neighbor or volunteer at a local soup kitchen.

[3]Potential: Visit your local library and look for appropriate books that talk about love, care and com­passion. Read stories and point out how characters expressed their love. _____, "How did the characters feel when they felt loved?"

[4]Talk: Coach your child to express his love in different ways. When we feel care and compassion towards others,the appropriate response is to show it. Talk about ways you can show -care and compassion with your child. These may include offering a kind word to a sad friend,helping someone in need,or doing something for someone that they cannot do for themselves.

[5]Considerations: Role-playing can be an effec­tive way to teach children new ideas. To role-play how to love others, set up a situation and act it out with your child. For example, pretend that one of his stuffed toys is not feeling well; ask him what he could do to help his toy feel better.

小题1:.. Complete the following sentence according to the underlined one in Paragraph 2. (no more than 5 words)

You should give your child chances of                  to teach him to love others.

小题2:. What does the underlined word “These” in Paragraph 4 refer to? (no more than 10 words)

小题3:.What's the author's advice for you on role-playing how to love others? (no more than 15 words)

小题4:. Fill in the blank in Paragraph 3 with proper words. (no more than 6 words)

小题5:.. What is the main idea of the text? (no more than 15 words)

单项选择题