--- Isn't that Ann's husband over there?--- No, it ______ be him---I'm sure he doesn't wear glasses.
Lily was talking to our teacher about examination, when suddenly Tom _______.
While I_________that he is an excellent leader,I don’t think he can do a good job in this company because he is too careless.
The two Chinese scientists have made a wonderful discovery, which marks a major _______ in the basic research in the field.
The incident caused a hot discussion on the Internet, but the local government had no immediate _______ on it.
The young violinist is very excited because the concert given by him has never been _____.