用所给单词的适当形式填空。
【小题1】Do you know how ____________ (protect) the Earth.
【小题2】What can we do ___________(keep) our city clean?
【小题3】--Look at the sign. You can’t talk here.
--Sorry. We ___________(not see) it just now.
【小题4】He would like____________ (go) shopping with you.
【小题5】What __________（make）the river dirty?
【小题6】Well ________(do), children!

It’s time ________ go to bed. (    )

A．to

B．for

C．and

Do you want _______ home? ( )

A．go

B．go to

C．to go to

D．to go

Do you want _________fish? （ ）

A．on

B．to

C．with

Would you like _________ shopping with me? (   )

A．to go

B．goes

C．going