_______ Japan’s nuclear crisis (核危机) will be solved in 2011 is not known yet.
| A．That | B．If | C．Whether | D．What |
He is a key ____________ in the murder so we must protect him from all kinds of danger.
| A．witch | B．watcher | C．wizard | D．witness |
Russia is _________ on the north of China.
| A．bounded | B．bound | C．boundary | D．lied |
Lately some scientists are experimenting ___________ white mice to ____________ this kind of medicine.
| A．on,try on | B．with, test on | C．on ,test out | D．with,carry out |
When the reached the top of the hill ,they _______________ so they had to stop for a rest.
| A．held their breath | B．out of breath | C．lost their breath | D．breathed deeply |
John ____________ his students is playing basketball on the playground.
| A．as well | B．as well as | C．and | D．together |