用所给词的正确形式填空。
【小题1】We should stop _________ (throw) rubbish into rivers.
【小题2】In the past, the Earth _________ (be) clean and beautiful.
【小题3】My brother is __________ (plant) trees in the backyard.
【小题4】The Earth __________(get) sick now.
【小题5】We shouldn’t __________ (cut) down so many trees.

His hobby  ____ playing basketball. ( )

A．are

B．is

C．\

It _____ October 27 yesterday .

A．is

B．are

C．was

There________ a toilet in my house. (    )

A．is

B．are

C．be

选词填空。
am   is   are
【小题1】Mom: ______ Sam doing his homework?
Amy: No, he isn’t.
【小题2】Mom: Are you tidying your room now?
Sam: Yes, I ______.
【小题3】Mom: Sam, what ______ you doing?
Sam: It’s a secret.
【小题4】Mom: ______ you drawing a picture, Amy?
Amy: No, I am not.