— I hear Prof.Huang will give us a talk ______ the History of Diaoyu Islands this weekend.— That’s great!A. on B. to C. at
The man is confident of himself when he is________the face of difficulties.
I can see some children________basketball in the playground now.
The boy was badly ill.He had to drop out of school because of________.
We shouldn’t________he trees in order to protect the environment.
The young man is________more famous than his father.