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

A. touch

B. pay

C. well

D. chose

Câu 1: We all regard pollution as a.......... matter to human beings.

A. solemn 

B. great

C. serious 

D. huge

Câu 2: The waste water from bath, showers, sinks and_______, and rainwater can be collected in a tank.

A. linguistic

B. official

C. dishwasher

D. operate

Câu 3: Gavin_______ the idea of dividing the rooms in half.

A. get on with

B. pave the way

C. keep an eye on

D. come up with

Câu 4: I_______ George on my way home.

A. dropped in on

B. gear up for

C. pair up with

D. look back on

Câu 5: The problem of_______ in big cities, which stems from uncontrolled migration from rural areas.

A. overpopulation

B. decrease

C. increase

D. growth

Câu 6: He had a new heart valve _______.

A. added

B. supplanted

C. improved

D. implanted