______ only 20 minutes to go before the train left, I felt uneasy in the taxi to the railway station.

 A. For                         B. With                       C. As                    D. Because

AIDS is said__________the biggest health challenge to both men and women in that area over the past few years.

 A．that it is        B．to be           C．that it has been    D．to have been

--- An ant has two stomachs --- one for itself, one for others.

--- Really? Quite interesting. I ____ anything about it.

A. don’t know      B. have known      C. haven’t known     D. didn’t know

__________twice a year, whether it is a car or bus or a truck, is the rule that every driver must obey in this city.

 A．Examining       B．Examined       C．Being examined    D．Having been examined

The famous scientist, _______ a dinner party will be held tonight,is to arrive soon.

A. in honour of him      B. in his honour      C. in whose honour    D. in which honour

 How long do you think it will be ________ the computer company puts forward a new product?

A. before             B. since             C. until               D. that

 By law,when one makes a large purchase, he should have _____ opportunity to change his mind.

A. accurate         B. adequate        C. urgent            D. excessive

 _____ the front door ___     , he had to enter the room through the back door.

A.Seen, painted                        B.Seeing, painted

C.Seeing, being painted                 D.Being seen, being painted

On hearing the news, the girl rushed out without hesitation , ___   the luggage ___   on the floor and ____ in the dark.

 A left, lied, disappeared                   B. leaving, lying, disappeared

 C. leaving, lie, disappeared                D. left, lay, disappear

I prefer a flat in the suburb to        in downtown , because I want to live near my Mom’s .

 A．one            B．that            C．it                D．this