____ wide spread of H1N1 is _____ challenge for the whole world. Confidence, cooperation and responsibility are keys to overcoming it.
| A．A; the | B．A; a | C．The; the | D．The; a |
---Bear in mind that you won't be able to cancel the contract ____you've signed.
--- I _____.
| A．unless; do | B．since; will | C．once; will | D．after; have |
The plan for a new office tower went ahead ______local opposition.
| A．not to mention | B．regardless of | C．on account of | D．in addition to |
-----Tom. You look very bored and tired.
-----Yes, I ______ my father on the farm until seven o’clock this morning.
| A．have been helping | B．had helped | C．was helping | D．am helping |
Jane is supposed to stop working. She has a serious headache because she ______ all the morning .
| A．wrote | B．is writing | C．had written | D．has been writing |
I’m worried about Doug, he’s _______ too much work. He looks awful.
| A．taking in | B．taking on | C．taking down | D．taking back |