题干

据报道,挪威和荷兰正在开发一种新能源﹣﹣盐能.当海水和淡水混合时,温度将升高0.1℃,世界所有入海口的这种能源相当于电力需求的20%,海水和淡水混合时,温度升高最可能的原因是(   )

A:由于浓度差产生放热

B:发生了水分解反应

C:发生了盐分解反应

D:盐的溶解程度增大

上一题 下一题 0.0难度 选择题 更新时间:2019-10-03 09:43:59

答案(点此获取答案解析)

A

同类题3

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    Whether rich or poor, parents who have books in the home increase the level of education their children will attain, according to a 20-year study led by Mariah Evans.

    For years, educators have thought the strongest predictor of attaining high levels of education was having parents who were highly educated. But, the study showed that the difference between being raised in a bookless home compared to being raised in a home with a 500-book library has as great an effect on the level of education a child will attain as the difference between having parents who are barely literate (有文化的) and having parents who have a university education.

    Being a sociologist, Evans was particularly interested to find that children of lesser-educated parents benefit the most from having books in the home. What kinds of investments should we make to help these kids get ahead? The results of this study indicate that getting some books into their homes is an inexpensive way that we can help these children succeed. Evans said, "Even a little bit goes a long way. Having as few as 20 books in the home still has a significant impact on motivating a child to a higher level of education, and the more books you add, the greater benefit the children get.”

    The researchers were struck by the strong effect having books in the home had on children's educational attainment even above and beyond such factors as education level of the parents, the father's occupation or the economic level of the country.

    Having books in the home is twice as important as the father's education level, and more important than whether a child was brought up in a developing country or a developed country. Surprisingly, the difference in educational attainment for children born in developed country and children born in developing country was just 2 years, less than two-thirds of the effect that having 500 or more books in the home had on children.