----I’m sure Andrew will win the first prize in the final.
----I think so. He ______for it for months.
A. is preparing                              B. was preparing     
C. had been preparing                       D. has been preparing

----How beautiful the university is, Professor Wu.
----So it is. I ______ here for four years and my daughter is studying here too.
A. studied           B. have studied     C. was studied     D. had studied

—_______ for Beijing?
—Yes, and I’ll come back in two months.

—Does your sister work as a teacher in Canada?
—No, but she once  _________there for five years．

I ___________ in the street when I met an old friend of mine  yesterday.

—Hi, Jack! When did you arrive in Berlin?
—Last weekend .I         a different culture since then.

— Isn’t it hard to drive downtown to work?
—Yeah, that’s why I ______ to work by train.

— Why does the lake smell terrible?
— Because large quantities of water______.          

My wife ______the night shift when my plane ______. That’s why no one is to meet me at the airport today.

—You didn’t go to Europe, why?
—I _____ this morning, but I _____ to Shanghai because of an emergency ．