My parents would have come to see you if it had been possible, but they __________ so busy.
| A．were | B．had been |
| C．have been | D．would be |
The prize of the game show is ＄30,000 and an all expenses ____ vacation to China.
| A．paying | B．paid | C．to be paid | D．being paid |
The woman ____ herself a writer has never written any books.
| A．calling | B．called | C．calls | D．to call |
___ the room, the nurse found the tape-recorder ___.
| A．Entering; stealing | B．Entering; gone |
| C．To have entered; being stolen | D．Having entered; to be stolen |
____ I understood very little French, I couldn’t follow their conversation.
| A．Although | B．Unless | C．Since | D．Before |
____ to light for a long time, the potatoes turned green.
| A．Introduced to | B．Exposed to | C．Linked to | D．Connected to |