用所给动词的适当形式填空。

1. They are trying______(save) the boy by doing everything.

2.—Why not______ (have)a rest?

   —Good idea.

3. You'd better______ (not play) football in the street.

4. When they______ (find) the lost child, the mother was very grateful.

5. He used to______ (take) a walk after supper.

6. They are used to______ (quarrel) with each other.

7. When the police arrived, the wounded (send) to the hospital.

8. If you are too lazy, you______ (not pass) the exam.

9. Jim said he ______ (come) from the USA.

10. Look! There is a cat ______ (climb) up the tree.