You should keep the window ________ because the room is too hot．

A．open

B．opening

C．opened

I think teenagers should ________ drive．They are not serious enough．

A．be allowed to

B．not be allowed to

C．not allow to

It will be ________ if you buy a return ticket on the train when you travel in England．

A．much cheap

B．more cheaply

C．much cheaper

"You can't have them all．You can choose ________ the kite ________ the toy car," said the mother．

A．either; or

B．not only; but also

C．both; and

I can never forget the stories ________ my grandma told me．

A．what

B．who

C．them

D．that

I began watching here an hour ago, but now nothing ________ yet．

A．happens

B．will happen

C．happened

D．has happened

________ I was in the US, I made a lot of American friends．

A．while

B．Although

C．Unless

D．Until

Everyone in the hall knew me, but I did not know ________．

A．him

B．her

C．them

D．those

________ this rock music, please．I'm afraid some people can't stand the noise!

A．Stopping

B．stop

C．Stops

D．Stopped

We make it a rule that each of us ________ the bedroom one day a week．

A．has cleaned

B．have cleaned

C．cleans

D．clean