Câu hỏi: Ecologists are trying to preserve our environment for future generations by protecting the ozone layer, purifying the air, and have planted the trees that have been cut down.

A. to preserve

B. for

C. the ozone layer

D. have planted

Câu 1: The master of ceremonies announced in a loud and clear voice and told that the dinner would be late due to unforseen circumstances.

A. of ceremonies

B. and told

C. would be

D. due to

Câu 2: This apprentice has spent two weeks to work on that new machine.

A. has spent

B. to work

C. on

D. new machine

Câu 3: Do most boys and girls give a great deal of thought to their future employ?

A. most

B. give

C. thought

D. employ

Câu 4: He was very surprised when he visited London, in that the drivers always drive on the left hand side of the street.

A. very surprised

B. when

C. in that

D. on

Câu 5: Unless there had been a heavy storm, the climbers will not have died.

A. Unless

B. had been

C. heavy

D. will

Câu 6: Today's job seekers are confronted with such question as "Are you computer literate?" and "Can you set up a data base?"

A. job

B. confronted

C. such question

D. set up