Look out ________ the stranger! He had a gun and he could not be a policeman!

[　　]

The spokeswoman said it was hoped that the European Union would play a key role in ________ the city after the war.

[　　]

When and where to go for the on-salary holiday ________ yet.

[　　]

A．are not decided

B．have not been decided

C．is not being decided

D．has not been decided

－What made you so happy?

－ ________ .

[　　]

A．To have replaced all the missing pieces

B．Having replaced all the missing pieces

C．Have replaced all the missing pieces

D．Replaced all the missing pieces

The students are advised ________ sunglasses to protect themselves ________ sunlight.

[　　]

Last year, I suggested he ________, but he didn't pay any attention. Now, he has a health problem. He has got lung cancer.

[　　]

A．gave up smoking

B．gave up to smoke

C．give up smoking

D．give up to smoke

Be careful! I don't want you to　　   burnt.

[　　]

Sage, a 19-year-old American, who used to study astronomy at a California college, likes to help us watch stars ________ space through telescope.

[　　]

They graduated in 2001 and ________ since.

[　　]

A．haven't heard from

B．have never heard from

C．haven't been heard from

D．have been not heard from

Two of the boys ________ while playing football.

[　　]