There are many interesting science experiments out there for young kids. You can surprise your friends and teachers with them. All you have to do is to put a little effort into it and you should have no problem coming up with an in?teresting science experiment. One such experiment is to show your friends and teachers that you can make mothballs (棒脑丸) dance!If you want to do it,first,be sure that you have got all the necessary sci?ence kits for your science experiment.

  What you need for this experiment is a glass filled half full with water. Add a little bit of vinegar to your glass of water,about 1/3 or 1/4 of a cup (60 ml) ,and one teaspoon (10 ml) of baking soda,and then carefully stir the mix?ture. Drop a few mothballs into the glass and have your audience watch. As long as the surfaces of the mothballs become fairly rough,they should begin to bounce up and down in the glass.

  You can also do a similar experiment with raisins (葡萄干) and clear pop,such as Sprite. In this experiment,all you have to do is to fill a glass with Sprite and drop a few raisins into it. The raisins should begin to bounce up and down in the glass of Sprite. You can also replace the raisins with mothballs and you should get the same effect in the Sprite. This project works because the irregular surfaces of the mothballs and the raisins hold some C0₂ bubbles (气泡) ，causing them to bounce up and down in a dancing motion.

1. The writer writes this passage to     .

   A. explain why some science experiments are easy

   B. encourage people to spend more time on science

   C. tell us how good he is at doing science experiments

   D. teach kids how to do an easy and interesting science experiment

2. What is the most probable name of the experiment?

   A. Producing mothballs.

   B. Dancing mothballs.

   C. Changing mothballs.

   D. Swimming mothballs.

3. Which of the following things are needed in the experiment? 

a. baking soda b. water c. mothballs

d. salt e. vinegar f. sugar

   A. beef   B. acde

   C. abed   D. abce

4. The underlined word "pop" in Paragraph 4  probably refers to a     .

   A. mothball

   B. kind of vinegar

   C. drink with bubbles

   D. special kind of raisin

5. From the last paragraph we can know .

   A. why Sprite has some C0₂ bubbles

   B. what people usually use Sprite for

   C. what scientists usually do with raisins

   D. why the mothballs bounce up and down

假定英语课上老师要求同桌之间交换修改作文，谙你修改你同桌写的以下作文。文中共有10处语言错误，每句中最多fl两处。每处错误仅涉及一个单词的增加、删除或修改。

增加：在缺词处加一个漏字符号(A) ，并在其下面写出该加的词。删除：把多余的词用斜线(\) 划掉。

修改：在错的词下画一横线，并在该词下面写出修改后的词。注意：1. 每处错误及其修改均仅限一词；

2. 只允许修改10处，多者(从第11处起) 不计分。

  Never shall I forget the first English lesson giving by Miss Liu. One Monday morning,when she entered into the classroom,we found that she was young and beautiful lady. Then she introduced her and said we shouldn't call her Teacher Liu but Miss Liu. Late,she let us go to the blackboard and said something about ourselves in English in turn. When it was my turn,I felt too shy that I didn't dare to say anything before the class. She went up to me and said kind, "Don't be afraid. I believe you can do it good. " At last,I went to the blackboard. She praised me for that I had done.

15. ― Hey,Jacky!I can give you a ride to the airport.

―You couldn't do any     (good) than that. I can save a lot of time that way!

14. Mr Black has never met     (strange) thing in the past 10 years.

13. My uncle's house in the downtown area is much smaller than ours,but it is twice     (expensive) .

12. The old man lives     (much) quiet life.

11.It may not be a great suggestion. But before     ( good) one is put forward,we will do with it.

10. If the manager has to choose between the two,he would say John was    (good) choice.

9. Christchurch is New Zealand's     (three,large) city after Auckland.

8. In ancient times,people rarely travelled a long distance and most farmers only travelled as     (far) as the local market.