资源看点：对所学基础知识进行分课练习，同步实用。

Lesson 57

I. 根据括号中所给的汉语用适当的词语填空。

1. Look! Some children are playing in the ____________（院子）.

2. Danny, please don’t put the ____________（垃圾）here and there.

3. How many __________（袋子）of rice are there on the truck?

4. The teacher ____________（解释）the sentences again, but I still didn’t understand it.

5. I have used up my paper. Would you please lend me some __________（张）?

II. 根据句意用所给动词的正确形式填空。

6. They have just finished ___________ (clean) up all the rooms.

7. It took us an hour ___________ (work) out those problems.