What ________ so many people to visit Guilin every year?

A．attracts

B．is attracted

C．attacks

D．attract

The girl couldn't stop crying ________ she felt very sad．

A．though

B．before

C．because

D．so

We had heard a lot about her ________ we saw her．

A．after

B．when

C．since

D．before

________ we were singing happily, he came in．

A．While

B．After

C．Until

D．Before

Class 1 is ________ large ________ Class 2．

A．so…that

B．as…as

C．such…that

D．so…as

I will write to you ________ I get there．

A．while

B．as soon as

C．as

D．since

The doctor didn't take a rest ________ the operation was over．

A．after

B．until

C．since

D．because

Take the medicine ________ you go to bed．

A．until

B．before

C．because

D．if

It has been three years ________ I studied English．

A．when

B．since

C．as

D．before

It was so hot last night ________ we couldn't sleep well．

A．that

B．until

C．when

D．if