I had been puzzled over the problem for over an hour without any result, all at once a solution flashed across my mind.
| A．while | B．when |
| C．then | D．as |
The reason ______ his coming to China is ______ he wants to study in China．
| A．why; that | B．why; because | C．for; that | D．for; because |
．The children are having a good time, ______ with sand, others with toys．
| A．some of them playing | B．some of them are playing |
| C．some of them | D．who playing |
It is obvious that talking about something behind others is what everyone will not ______．
| A．come up with | B．put up with |
| C．keep up with | D．catch up with |
．The media today can draw public attention to _______help is actually needed．
| A．that | B．which | C．where | D．whose |
____ the end of the performance did the audience get the chance to take photos with the respectable actor．
| A．At | B．By | C．Up to | D．Not until |