.I just wonder _____ that makes him so excited.
| A．why it is | B．what it is | C．why is it | D．what is it |
He has given me so much help that I really wanted to do something for him ________.
| A．in return | B．by turns | C．in turn | D．in case |
Mr. Li is absent today. What do you consider ________ to him?
| A．happens | B．is happened | C．happening | D．has happened |
The reason ________ he refused to attend the meeting was that they didn’t give him an invitation earlier.
| A．how | B．which | C．why | D．because |
Our English teacher requested that the homework ________ tomorrow morning.
| A．would be handed in | B．be handed in |
| C．hand in | D．must be handed in |
Smoking, which may be ________ fun for some people, is ________ cause of discomfort for the people around him.
| A．/; a | B．a; a | C．a; / | D．a; the |