在横线上填入单词的适当形式。
1. It________(be) Helen’s birthday yesterday.
2. Listen, the children_________(play) the guitar now.
3.This is not ______(I) comb. It’s _______(she).
4. Mike ______ (do) some _______ (read) in the library every Monday.
5. The children _______ (plant) the trees on the hill this morning.