There isn’t a single person (    )I can turn to for help.

A. to whom   

B. where   

C. whom　　 

D. from

I was telling them about the village (    ) I visited last summer.

A. where　　

B. the one   

C. whom　　  

D. which

This is the second letter （　　 ）I received after I came here.

A. the  

B. when 

C. that 

D. all

I was really anxious about you. You _______ home without a word．

A．mustn’t leave

B．shouldn’t have left

C．couldn’t have left

D．needn’t leave

Visitors ______ not to touch the exhibits.

A．will request

B．request

C．are requesting

D．are requested

The research is so designed that once ________ nothing can be done to change it.

A．begins

B．having begun

C．beginnings

D．begun

Having a trip abroad is certainly good for the old couple, but it remains _______ whether they will enjoy it.

A．to see

B．to be seen

C．seeing

D．seen

All morning as she waited for the medical report from the doctor, her nervousness_______.

A．has grown

B．is growing

C．grew

D．had grown

It is hard ________ him ________ change his mind.

A．of you to make; to

B．for you to make;不填

C．for you to make; to

D．of you making;不填

I ________ my homework since lunch time．I’m very tired now.

A．have been doing

B．have done

C．have been done

D．did