问题

Everyone_____dohisbesttomaketheworldsafeandclean.
A:can
B:may
C:should
D:hadto
B:may
C:should
D:hadto
正确答案是:
同类题型
My parents are strict _________ their work and they are also very strict ________ me.
Did you have _____ great fun at the party—— Yes. It’s ______ great pity that you missed it.
__ I am concerned, I think the project should be held off right now
15—-Ken,, but your TV is going too loud —–Oh, I’m sorry I’ll turn it down right now