--Who______ it be that is knocking at the door?--It ______ be Father, but I’m not sure.
I feel so excited! At this time tomorrow morning I to Shanghai.
Here camewordhe got the first in the competition .
There are ______ students in the school . But I don’t know _______ the girls among them .
–Does he know how to work out the problem ? -Yes , he has ________ a good idea to solve it .
High school students should be given enough sleeping time , _______ they are busy with their study .