People did not discover AIDS until 1981
A.Not until 1981 had people discover AIDS
B.Not until 1981 did people discover AIDS
C.Not until 1981 people discovered AIDS
D.Not until 1981 then did people discover AIDS

A.agriculture
B.diverse
C.service
D.certainty

English / become / effective / medium / international / communication.
A.English has become an international communication of effective medium.
B.English has become an effective international communication of medium.
C.English has become an effective medium of international communication.
D.English has become an effective medium of become international communication.

A.development
B.entertainment
C.education
D.nationality

The ________ to make quick decisions is vital in an emergency.
A.knowledge
B.ability
C.talent
D.skill

A.mechanic
B.scholarship
C.champagne
D.chemist

All of the following statements can be inferred from the text EXCEPT ______
A.We need more and more water.
B.The population of the world is increasing every year.
C.Most of the world’s water is locked in glaciers and icecaps.
D.Factories also need more water.

Neither Tom nor his friends________ there last night.

A.is
B.are
C.was
D.were

Aren’t you fed up _____ the same thing every day?
A.of doing
B.with doing
C.with do
D.on doing

Nobody was injured in the accident, ______?
A.were they
B.did they
C.was he
D.did he