our earth, or else it will be no longer fit for us to live on.

Don’t complain ________ your teachers________doing too much homework, because they want you to be the best.

What about _____hiking thisafternoon? –Great.I’d like withyou.

She’s developing intosomeone who’s going to become very poor and require ______.

( )28.－_____ you put away your books－Yes,mum. I’ll do it at once.