9．　　　　　　 　　　　　　　 10．　　　　　　 　　　　　　 11．　　　　　　 　

　 根据句意及首字母，补全单词。

　 I like science! I like to do experiment．

　 One day，I put an egg (6)i　　　 　a glass of water．I (7)O　　　 　that the egg sank down the water(8)q　　　 ．Then I put a spoon of salt in it．I watched what would happen．But the egg was still in the (9)b　　　 　of the water。(10)N 　　　　happened to it! Why? I thought and thought carefully．“Maybe I need to put more salt．”I said to (11)m　　　 ．Another spoon of salt was put into the water．I took a chopstick and mixed(搅拌)the water again and again．A moment later，I was (12)s　　　 　to see the egg rising slowly from the bottom．Soon it went up on the surface．I tried to (13)p　　　 　it down，but it came up again．“Oh! Wonderful!” I shouted．I did the experiment successfully．How happy I was! By the experiment I knew a (14)t　　　 　that the buoyancy(浮力)of brine(盐水)is bigger than that of fresh water．

　　 It’s helpful for us to do experiment．It can make us learn more knowledge and know about the world．I hope to be a(15)s　　　 　in the future．What about you?

6．　　　　　　 　　　　　　　 7．　　　　　　 　　　　　　　 8．　　　　　 　　

40．Which sign means you can’t go straight?

39．--Do you know 　　　　　　?

--I’m not sure．Maybe she is a driver．

A．who the pretty woman is　　 　　　　　　　　　　　 B．who is the pretty woman

C．What the pretty woman does　　 　　　　　　　　 D．what does the pretty woman

38．The old mall 　　　　　　the bike and hurt his leg．

A. fall off　　 　　　　　　　　　　 B．fall down　　 　　　　 C．fell off 　　　　　　　　　 D．fell down