问题 选择题

欲将某温度下接近饱和的硝酸钾溶液变成饱和溶液,不能采取的措施是(  )

A.加入硝酸钾晶体

B.蒸发一定量水

C.给溶液加热

D.给溶液降温

答案

不饱和硝酸钾溶液加入硝酸钾,继续溶解至不能再溶解而成为饱和溶液,恒温蒸发水分,因溶剂减少而使不饱和溶液达饱和,降低温度,使同量水溶解硝酸钾的量减少而达到饱和.升高温度却只能使饱和溶液变成不饱和溶液,不饱和溶液更加不饱和.

故选C

选择题
阅读理解

阅读表达

    阅读下面的短文,根据短文后的要求答题(请注意问题后的词数要求)

     An American friend of mine who was high up in a big corporation had worked out a way of handling

a flood of e-mails before most of us had even heard of the concept. If any information he was sent was

vital enough, his lack of response would ensure the sender rang him up. If the sender wasn't important

enough to have his private number, the communication couldn't be that important, My friend is now even

more senior in the same company, so the strategy must work.    

     Almost every week now, there seems to be a report suggesting that we are all being driven crazy by

the bother of e-mail. If this is the case, it's only because we haven't devel-oped an appropriate

discrimination in dealing with it.      

              Firstly, you junk anything with an exclamation mark or a string of capital letters,or from any

address you don't recognize or feel confident about.    

     Secondly, e-mails don't all have to be answered. Because e-mailing is so easy, there's a tendency for

correspondence to carry on for ever, but it is permissible to stop an endless dis-cussion or to accept a

point of information sent by a colleague without acknowledging it.    

     Thirdly, a reply e-mail doesn't have to be the samelength as the original. We all have e-mail pals who

send long, chatty e-mails, which are nice to receive, but who then expect an equally long reply. Then

charm of e-mail can consist in the simple, incomplete sentence, totally regardless of the format of the

letter sent by post. You are perfectly within the bounds of politeness in responding to a marathon e-mail

with a brief reply.    

1. Which sentence in the passage is the closest in meaning to the following one?      

The possible existence of annoyance results from our inability to sort out e-mails.      

________________________________________________________      

________________________________________________________    

2. Fill in the blank in Paragraph 3 with a proper sentence.(within 10 words)        

______________________________________________________    

3. What advice is given in the last paragraph?  (within l0 words)        

______________________________________________________    

4. For what purpose does the author mention his American friend in Paragraph l? (within 10 words)       

 ______________________________________________________    

5. Translate the underlined sentence in the last paragraph into Chinese.        

_____________________________________________________