--- I take the book out?---I'm afraid not.
It’s believed that our moods are sometimes by colours. Many scientists are doing some research (研究) on this subject.
---- Do you know MoYan, the first Chinese citizen to win the Noble Prize?---- Yes, of course, his books are worth ________.
----I think it’s impossible for us to work out the plan in just two days. It’s too difficult.----You’re right. We can’t be _______ careful and hard while working on it.
Read this article, you’ll understand that not everything can be bought with money.
----What do you think of Frank?----He’s boy and he shows great interest in anything new.