—Look, the paint is starting to come off ______ the wall is damp.
—Well, we’d better have the wall repainted some day.
| A．when | B．once |
| C．if | D．where |
Barack Obama delivered a speech to 500 local youths during his visit to China, many of ____ from Fudan
University and Tongji University.
| A．them | B．whom | C．which | D．who |
---What’s your impression of the Great Wall?
---Wonderful! Once ____ , it can never be forgotten.
| A．seen | B．seeing | C．being seen | D．saw |
____ that you are chosen to be a volunteer at the London Olympic Games, what will you do?
| A．Assumed | B．Assuming | C．To assume | D．To be assumed |
He didn’t regret saying what he did but felt that he ____ it differently.
| A．could express | B．would express | C．could have expressed | D．must have expressed |
If China’s space technology has achieved ____ breakthrough in this field, it really is ____ amazing wonder.
| A．the; an | B．a; an | C．不填; the | D．a; 不填 |