—Johnson is indeed a wise man.
—Oh, yes. How often I have regretted ______ his advice!
| A．to take | B．taking |
| C．not to take | D．not taking |
---You must obey every word of mine!
---_______ I don’t?
| A．How if | B．What if | C．Even if | D．Only if |
How long do you think it will be _______ China sends another manned spaceship to the moon?
| A．when | B．until | C．that | D．before |
---________by the chemistry teacher for not finishing homework independently makes him feel very shameful.
---Yes. But he told me this morning he would spare no efforts to be the top one in our class.
| A．Scolded | B．Having scolded |
| C．Being scolded | D．After being scolded |
So absorbed ________ in the research that she didn’t hear someone knocking at the door.
| A．she did | B．did she | C．she was | D．was she |
______ you do the experiment carefully, you would make discoveries others wouldn’t make.
| A．Should | B．Would | C．Could | D．Might |