1 . The lecture ________, a lively question-and-answer session followed.

A．being given	B．having given
C．to be given	D．having been given

2 . Having been attacked by terrorists, ____________________     .

A．the tall building collapsed

B．doctors came to their rescued

C．an emergency measure was taken

D．warnings were given to tourists

3 . ________ from heart trouble for years, Professor White has to take some medicine with him wherever he goes.

A．Suffered

B．Suffering

C．Having suffered

D．Being suffered

4 . The old man, _______ abroad for twenty years , is on the way back to his motherland.

A．to work

B．working

C．to have worked

D．having worked.

5 . _____in the queue for half an hour, Tom suddenly realized that he had left his wallet at home.

A．To wait	B．Have waited
C．Having waited	D．To have waited

6 . __________ the program , they have to stay there for another two weeks.

A．Not completing

B．Not having completed

C．Not completed

D．Having not completed

7 . _________ to reach them on the phone, we sent an email instead.

A．Fail

B．Failed

C．To fail

D．Having failed