Câu hỏi: We all regard pollution as a.......... matter to human beings.

A. solemn 

B. great

C. serious 

D. huge

Câu 1: We kept in _______for a while after college.

A. touch

B. pay

C. well

D. chose

Câu 2: You need to_______ the numbers properly in a column.

A. align

B. check

C. draw

D. write

Câu 3: He had a new heart valve _______.

A. added

B. supplanted

C. improved

D. implanted

Câu 4: All the _______had excellent academic credentials.

A. candidates

B. goverments

C. followers

D. desigers

Câu 5: Installing is firewall is one method of trying to protect against_______.

A. hackers

B. thiefs

C. robbers

D. crooks

Câu 6: The problem of_______ in big cities, which stems from uncontrolled migration from rural areas.

A. overpopulation

B. decrease

C. increase

D. growth