—I remember you were a talented pianist at college.Can you play the piano for me?

—Sorry，I ________ the piano for years.(2012·湖南)

A．don't play B．wasn't playing

C．haven't played D．hadn't played

— Alvin，are you coming with us?

—I'd love to，but something unexpected ________.

A．has come up B．was coming up

C．had come up D．would come up

In the last few years thousands of films ________ all over the world.

A．have produced B．have been produced

C．are producing D．are being produced

By the time Jack returned home from England，his son ________ from college.(2011·辽宁)

A．graduated B．has graduated

C．had been graduating D．had graduated

We arrived at work in the morning and found that somebody ________ into the office during the night.(2011·江西)

A．broke B．had broken

C．has broken D．was breaking

—Hurry up！Alice and Sue are waiting for you at the school gate.

—Oh！I thought they ________ without me.

A．went B．are going

C．have gone D．had gone

John, a friend of mine, who got married only last week, spent $3,000 more than he ________ for the wedding.

A．will plan B．has planned

C．would plan D．had planned

In the near future，more advances in the robot technology ________ by scientists.(2011·湖南)

A．are making B．are made

C．will make D．will be made

His sister left home in 1998，and ________ since.

A．had not been heard of B．has not been heard of

C．had not heard of D．has not heard of

—Why does the lake smell terrible?

—Because large quantities of water ________.

A．have polluted B．is being polluted

C．has been polluted D．have been polluted