He _________ in American for five years, and now he works in Shanghai.
| A．have worked | B．worked | C．had worked | D．have been working |
She won the first prize in the speech contest and __________surprised us.
| A．which | B．it | C．as | D．who |
Li Fang is very busy，__________she’s always helping others with their lessons.
| A．but | B．although | C．so | D．for |
—Helen must obey her parents.
—Oh，she must，__________?
| A．must she | B．mustn’t she |
| C．shouldn’t she | D．should she |
We must do the experiment carefully__________Miss Liu told us.
| A．what | B．since | C．as | D．while |
__________ everybody is here，let’s set out right away.
| A．Now that | B．Because |
| C．For | D．After |