The boy is most___________to make a great difference in the future, because he is so bright. Besides, he works extremely hard.
He is a friend ______ can help you in time of need.
The most important thing ______ we should pay attention to is the first thing ______ I have said.
This is the only one of these books that ______worth reading.
The man ______ talked to you just now is my father.
They thought too much about ______.