Such changes can alter the social structure,（）people to move.

单项选择题There are many cities（）very fast.

A.expanding
B.expands
C.expanded
D.expand

单项选择题Civil war or regional conflicts also cause disruption,（）people out of rural areas.

A.drives
B.drove
C.driving
D.driven

单项选择题This growth,（）mainly in Southeast Asia and Africa, has dramatic consequences.

A.happens
B.which is happening
C.which happening
D.which happened

单项选择题Sixty million people who（）in rural areas are moving to cities every year.

A.lived
B.lives
C.living
D.live

单项选择题I spent most of my money in the first week and（）had very little for food at the end of the holiday.

A.since
B.however
C.moreover
D.consequently

单项选择题He is trying to find a new way to（）a living. Which of the following is incorrect.

A.get
B.earn
C.take
D.make

单项选择题Several languages are likely to die（）

A.out
B.down
C.off
D.of

单项选择题Heat causes the（）of gas.

A.growth
B.increase
C.expansion
D.extension

单项选择题He is（） at doing this kind of job.

A.imefficient
B.nonefficient
C.unefficient
D.inefficient

单项选择题Cycling is a good exercise.（）, it doesn't pollute the air.

A.Therefore
B.Moreover
C.But
D.However