用所给词的正确形式填空。
1.I think there _____(be) fewer trees next year.
2.He _____ (collect) 300 pictures since 5 years ago.
3.Sam always _____(help) his classmates.
4.Would you mind _____ (play)the games after school?
5.My father came into the bedroom while I ____ (dance)
6.American fast food seems_______ (be) the most popular in the world.
7.My mother made me ______(clean) my room all by myself yesterday.