Jack wasn’t saying anything，but the teacher smiled at him________he had done something very clever(2011·湖南，33)

It is not immediately clear__________ the financial crisis will soon be over

I feel a little hungry, Mom.–There are some pieces of bread on the plate. You can take ______.

How do you like the two pairs of trousers— They don’t fit me very well. They are ________ too long _________ too short.

What do you want to be when you________—A doctor.