Today is your grandma’s birthday. Let’s  to see her

A．to go

B．go

C．goes

D．going

I can learn ________ ping­pong. (    )

A．to play

B．plays

C．playing

I want ______your friend. ( )

A．be

B．to be

C．to

It's time go home.    (    )

A．to

B．/

C．for

用所给单词的适当形式填空。
【小题1】Water is very________(use).
【小题2】We use wood________(make) chairs.
【小题3】Trees help________(keep) the air clean.
【小题4】________(protect) the Earth, we should________(save) water.
【小题5】Look! They________(do) a project.
【小题6】Please tell________(they) about Christmas.
【小题7】He starts________(sing).