问题 填空题

下列各种物质中:①水银  ②甲烷  ③石灰水  ④硫酸铜  ⑤海水  ⑥液氢⑦黑火药

属于纯净物的是(填编号,以下同)______;属于混合物的是______;属于单质的是______.

答案

石灰水是氢氧化钙的水溶液;海水中含有氯化钠、水等物质;黑火药是由硝酸钾、硫磺、木炭组成的;以上物质均是由多种物质组成的物质,均属于混合物.

水银、甲烷、硫酸铜、液氢中均只含有一种物质,均属于纯净物.

水银、液氢是由同种元素组成的纯净物,属于单质.

故答案为:①②④⑥;③⑤⑦;①⑥.

阅读理解

To learn English well you must learn about yourself. You must discover what your own special needs are in English. You should pick out what makes English different from your own language and concentrate on those parts. And above all, you should pick out your own personal weaknesses in English, pick out your own special problems, find out what mistakes you most often make and   make a list of them.

It will be best if, in your preparation, you can practise doing the various sorts of work you will be asked to do in examination. You should then make a careful note of any mistakes you make more than once. Count up how many times you make each mistake, and the mistake you make most often should be at the top of your list, the next most common in second place, and so on.

For example, if your own language is Japanese, you may find the problem of articles comes at the top of your list. If you speak German, you may find using some of the conjunctions is your biggest problem. If your mother tongue is French, you find you are always having trouble with some of prepositions. And if Italian is your language, you may constantly forget to use a suitable pronoun when you should.

But these are only examples of mistakes typical of certain languages. They may or may not

be your particular personal mistakes. As I say, these personal ones are the most important of all to discover.

小题1:

To learn English well the most important thing is to ______.

A.learn about yourself as much as possible

B.discover your own special needs in the language

C.find out the difference between your own language and English

D.pick out your own personal weaknesses in English小题2:

The writer advises the readers to ______ .

A.spend as much time on English as possible

B.take examinations of various sorts

C.find out their own problems in doing selected exercises

D.keep a notebook with the important languages points in it小题3:

The first item on the list should be the mistake you make ______ .

A.more than once

B.many times

C.most often

D.very often

单项选择题