Câu hỏi: Certain courses are compulsory; others are optional.

A. voluntary

B. free

C. pressure

D. mandatory

Câu 1: Population growth rates vary among regions and even among countries within the same region.

A. fluctuate

B. stay unchanged

C. restrain

D. remain unstable

Câu 2: His policies were beneficial to the economy as a whole.

A. harmless

B. crude

C. harmful

D. good

Câu 3: You did a beautiful thing in helping those poor children.

A. meaningful

B. good

C. terrible

D. positive

Câu 4: We offer a speedy and secure service of transferring money in less than 24 hours.

A. slow

B. open

C. unsure

D. uninterested

Câu 5: I have a modest little glass fish tank where I keep a variety of small fish.

A. moderate

B. limited

C. narrow

D. large

Câu 6: Barry seems happy enough working for himself.

A. funny

B. satisfied

C. upset

D. interested