____puzzled the mother most was____the son would never agree with her.
| A．What;why | B．That;how | C．Which;when | D．What;where |
He is a man of few words, and seldom speaks until _______ to.
| A．spoken | B．speaking |
| C．speak | D．be spoken |
Though I have often heard this song _______. I have never heard you _______ it.
| A．being sung, sang | B．sang, singing |
| C．sung, sing | D．to be sung, to sing |
Tony was very unhappy for _______ to the party.
| A．having not been invited | B．not having invited |
| C．having not invited | D．not having been invited |
The research is so designed that once _______ nothing can be done to change it.
| A．begins | B．having begun |
| C．beginning | D．begun |
After graduation she reached a point in her career __________ she had to decide what to do.
| A．that | B．what |
| C．which | D．where |