It is these poisonous products_____can cause the symptoms of the flu , such as headache and aching muscles .

A. who          B. that          C. how   D. what

The museum where we visited yesterday has a history of 200 years.

                A                   B  C       D 

 Now that you have a job ,you should devote yourself to ____you do at work.

A. whatever     B. no matter what        C. however     D. no matter how

They have to work on Sundays,_____they don’t like .  

A.but      B.so      C.that      D.which

I need one more stamp before my collection _______.

has completed   B. completes  C. has been completed    D. is completed

Tony can’t have received the invitation. ________, he would have attended your birthday party yesterday.

A. Therefore     B. Otherwise    C. However      D. Besides

I try to understand __________ that prevents so many Chinese from being as happy as one might expect.

A. why is it        B. what is it      C.why it is       D.  what it is

-----Alice looks blue today.

-----Yes, I asked her, but she wouldn’t say _____ troubled her.

A.why was it that      B. that was why        C. it was what        D. what it was that

_______parents say and do has a life-long effect on their children.

A.That         B.Which           C.What              D.As

--- It’s thirty years since we last met.

 --- But I still remember the story, believe it or not, _________we got lost on a rainy night. 

    A. which       B. that       C. what          D. When