1 . ---I called your office at about ten this morning, but there was no reply．
---Oh, that was probably __________ I was paying a visit to a friend in hospital．

A．when

B．why

C．what

D．that

2 . _______ I’m willing to help, I don’t have much time available.

A．As

B．While

C．As though

D．Since

3 . This discovery helped researchers conclude that these two drugs, when ___ together, could lead to heart disease.

A．taken

B．taking

C．to take

D．having taken

4 . The manager put forward a suggestion        we should have an assistant. There is too much work to do.

A．whether

B．that

C．which

D．when

5 . The police____to the spot____order immediately.

A．was sent; to keep	B．were sent; keeping
C．was sent; keeping	D．were sent; to keep

6 . We were all confused why   he   left the job____he was so well paid in that big company.

A．if

B．until

C．once

D．when

7 . The book is of great help to ______ wants to do the job.

A．who

B．whomever

C．no matter who

D．whoever

8 . This is an illness that can result in total blindness if ______.

A．to leave untreating	B．left untreated
C．leaving untreating	D．is left untreated

9 . You may think of giving up study, in ____________ case just think it over before making the decision.

A．that

B．which

C．whose

D．where

10 . ____________ small a population an ethnic group has, it has a rich history.

A．Though

B．While

C．However

D．Whatever