We can achieve a lot when we learn to let our differences unite , rather than _______ us.

A. divide B. reject C. control D. abandon

Silk ______ one of the primary goods traded along the Silk Road by about 100 BC.

A. had become B. reject

C. control D. abandon

To return to the problem of water pollution , I'd like you to look at a study _______ in Australia in 2012.

A. having conducted B. to be conducted

C. conducting D. conducted

Scientists have advanced many theories about why human beings cry tears , none of ______ has been proved.

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

When their children lived far away from them , these old people felt ______from the world.

A. carried away B. broken down

C. cut off D. brought up

A sudden stop can be a very frightening experience , ______ if you are travelling at high speed.

A. eventually B. strangely

C. merely D. especially

When the time came to make the final decision for a course , I decided to apply for the one that ______my interest.

A. limited B. reserved

C. reflected D. spoiled

Had the governments and scientists not worked together , AIDS-related deaths _______ since their highest in 2005.

A. had not fallen B. would not fall

C. did not fall D. would not have fallen

In this article , you need to back up general statements with ________ examples.

A. specific B. permanent

C. abstract D. universal

George _________ too far . His coffee is still warm .

A. must have gone B. might have gone

C. can't have gone D. needn't have gone