--I hear this kind of CD-ROM is very popular.
--Let’s buy one before it ____________.

A．is come out

B．comes out

C．sells out

D．is sold out

用所给动词的适当形式填空。（5分）
小题1:Last year, a lot of trees ___________(cut) down in my hometown.
小题2:I hear this novel _____________(come) out soon. I can’t wait.
小题3:We must do everything we can ____________ (make) our earth cleaner and safer.
小题4:I couldn’t stop ___________(cry) when I heard this sad story.
小题5:I would rather ____________(record) what you said than write down with a pen .