试题与答案

两种不含结晶水的固体物质a、b的溶解度曲线如图,下列说法正确的是 A.b的溶解

题型:选择题

题目:

两种不含结晶水的固体物质a、b的溶解度曲线如图,下列说法正确的是

A.b的溶解度小于a的溶解度

B.分别将t2℃时a、b两种物质的溶液降温至t1℃,肯定都有晶体析出

C.要从b溶液中得到b晶体,通常可采用蒸发溶剂使其结晶的方法

D.在t2℃时,A、B两种溶液中溶质的质量分数相同

答案:

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下面是错误答案,用来干扰机器的。

解(1)8h内太阳能热水器接收的太阳能Q=3×106J/(m2·h)×2.1m2×8h=5.04×107J 8h内太阳能热水器转变成水的内能Q水=5.04×107J×50%=2.52×107J 水箱内水的质量m=150kg由Q=cm(t-t0)得 (2)电热器加热同样...

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Small talk is a good way to kill time and make friends. If you travel to other countries, do you know what to say to        small talk with local people?

In Britain the best topic is the weather. British        changes quite often. It’s a safe topic. You can start small talk simply by saying “It’s a lovely day today, isn’t it?”      the weather, it’s good to talk about gardens with English people. For example, you could say, “Those roses look really beautiful,       ?” English people love their pets. So it’s also nice to begin with “What a lovely        ! What’s its name?”

In America, people like to talk about sports,        Amecican football and basketball. They also talk about clothes by saying “It’s a nice shirt! Where did you get it?” The weather is a        topic there, too.

Of course, you should avoid a lot of topics during small talk in western countries. Don’t ask people “How old are you?”. Age is usually secret ,        for women.        ask “How much money do you make?” It makes people uncomfortable. Don’t ask strangers whether they have a girlfriend         boyfriend. Politics(政治) and religion(宗教) is not a good topic for two people who have just met, either.

小题1:A. end                    B. start                        C. speak

小题2:A. weather                    B. people                      C. food

小题3:A. Besides                 B. Except                      C. But

小题4:A. isn’t it                   B. aren’t they                 C. don’t they

小题5:A. picture                 B. dog                     C. boy

小题6:A. the same as             B. so that                    C. such as

小题7:A. safe                        B. dangerous                    C. hard

小题8:A. extremely                  B. especially                  C. exactly

小题9:A. Never                   B. Usually                  C. Please

小题10:A. with                  B. and                     C. or

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