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问题 选择题

地球上71%的面积覆盖着水，水是生命之源，也是重要的溶剂，下列说法正确的是（　 ）

A．生石灰与烧碱溶于水都有热量放出，不能用加水的方法鉴别二者

B．溶质在溶解的过程中，有的放出热量，有的吸收热量

C．常温下KNO3、Ca(OH)2的饱和溶液降温后仍是饱和溶液

D．将NaCl、蔗糖溶于水后，溶质均以离子形式存在

答案

答案：B

题目分析：水是重要的化学物质，生命离不开水，水也是一种通用的常见溶剂，本题涉及的选项与溶液、溶解等结合起来。A选项中生石灰与烧碱溶于水均放热是正确的，但是生石灰溶解度小，一般会出现浑浊或者大量沉淀，烧碱溶于水后是无色透明的溶液，故还是可以区分；B选项对于溶解放热、吸热的表述是正确的；C选项中KNO3随温度的升高溶解度增大，而Ca(OH)2随温度的升高溶解度反而减小，故降温后，Ca(OH)2不是饱和溶液；D选项中蔗糖溶于水成蔗糖溶液，里面溶质是蔗糖分子，不是离子形式。故选择答案B。

点评：注意常见物质的溶解及溶解度等重要概念的运用。

单项选择题

まだ若い（　　　　　）、やりたいことをやっておこう。

A．うちに

B．前に

C． ところ

D． 中で
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单项选择题

The Supreme Court will hear arguments about the use of public money for the private schooling of children with special needs. It’s interesting to note what’s not at issue: namely, that when a public school system is unable to provide an appropriate education, it is obligated to pay the costs of private school. Too bad poor children don’t have that unshakable right; if they did, there would be no controversy about the District program that gives vouchers to low-income children to attend private schools.

The case to be heard by the court hinges on whether parents have to enroll a child with special needs in public school before the child can attend private school at public expense. Special-education advocates say students shouldn’t have to waste time before being placed in a setting that best suits their needs, while school boards worry about a ruling that could amount to an unfettered fight to private schooling at public expense. What strikes us about the emotionally charged debate is the acceptance by both sides that sometimes it is appropriate to use public money to pay for a child to go to a private school. So, why all the arguments about the approximately$14 million for a federally funded program that lets 1,700 D. C. students attend private schools instead of failing public schools

To hear critics of the D. C. Opportunity Scholarship Program tell it, the use of public money for private schooling is as unprecedented as it is undesirable. In addition to the billions of dollars spent annually on private school tuitions for students with disabilities, private schools get public money for books, technology and teacher training. As long as the money is seen as benefiting the child, it is considered a proper, even desirable, use of public dollars.

Don’t get us wrong. We’re not arguing for the unilateral right of parents to enroll their sons and daughters in any school they wish with the taxpayers picking up the bill. Abuse of special-education policies has contributed to increased costs that threaten to take needed money from general public education funds. Safeguards are needed. Public schools should be pressed to do a better job for students with disabilities and students without. But there are schools in Washington where statistics show that failure is almost guaranteed. If a school system can’t educate a child—whether because of acute special needs or its own historical failings—why should that child not have options for a " free appropriate public education "

What does the word " unfettered " (Line 4, Para. 2)mean（）

A. Unlimited

B. Extreme

C. Unwanted

D. Ultimate
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