Câu hỏi: This_______disease caused a lot of complications during the treatment procedure.

A. situation

B. difficult

C. life-threatening

D. weak

Câu 1: He had a new heart valve _______.

A. added

B. supplanted

C. improved

D. implanted

Câu 2: We kept in _______for a while after college.

A. touch

B. pay

C. well

D. chose

Câu 3: The _______ by UN troops prevented fighting from breaking out.

A. participant

B. intervention

C. joiner

D. contestant

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: _______ does not exist yet, but scientists are working hard to create computers that can think like human beings.

A. Advancement

B. Destruction

C. Intervention

D. Artificial intelligence