10. Please look carefully before you _______ (cross) the street.

9.　 My mother made me _____ (clean) my room all by myself yesterday.

8.　 They ______ (eat) a lot of potatoes yesterday, so did I.

7.　 American fast food seems _______ (be) the most popular in the world.

6.　 If you want to cross a street, you _______ (wait) for the green light.

5.　 My father came into the bedroom while I _______ (dance).

4.　 Would you mind _______ (play) games after school?

3.　 Sam always ______ (help) his classmates last term.

2.　 He _____ (collect) 300 pictures since 5 years ago.

1．I think there ________ (be) fewer trees next year.