We        the difficulty together, but why didn’t you tell me?

A．need have faced    B．can have faced     C．could have faced    D．must have faced

We _____to Sydney next Monday. What about having a party this weekend?

 A. have flown    B. flew  C. are flying  D. had flown

I really don’t know how to thank you , but for your help, I ______ my lost necklace．

A．couldn’t have found                    B．mustn’t have found

C．couldn’t find                          D．wouldn’t find

Her sister ______ a rich man. They ______ for twenty years.

A．married with; have married

B．married to; have married

C．married; have been married

D．has married with; have been married

—I'm going to travel along the Mekong River next week.

—______________.