It was not until 1920 ________ regular radio broadcasts began.

A. while　 B. which　 C. that　　 D. since

I ______an old picture of my childhood when I sorted out the books.

Does the way you thought of______the water clean make any sense?

A.making 　 B.to make　 C.how to make 　 D.having made

The seller would sell the shirt for ten yuan, but the customer ________ eight yuan．

　 A．sold　 B．offered　 C．charged　 D．asked

Martin visited his aunt two days before he _____ town.

A. left     B. will leave    C. had left     D. is going to leave

他急于想知道这次选举的结果。(be anxious to do)

He looked around and caught a man ______ his hand into the pocket of a passenger.

A. put　　　　　　　　　　　 B. to be putting

C. to put　　　　　　　　　 D. putting

Linyi isn’t what it used to be. The last decade 　　　　great changes in the city image.

A．witnessed　　 B．was witnessing　　　　　　　 C．has witnessed　　　 D．had witnessed

She must be very tired. _______so many little children is a very hard job.
  A. To have looked after    B. Having looked after     B. Look after   D. Looking after

Unless___________to speak, you should remain silent at the conference.

A.invited　　　　　　　 B.inviting

C.being invited　　 D.having invited