Câu hỏi: Some______ animals become tame if they get used to people.

A. wild

B. domestic

C. endangered

D. rare

Câu 1: He had a new heart valve _______.

A. added

B. supplanted

C. improved

D. implanted

Câu 2: The society was set up to______ endangered species from extinction.

A. prevent

B. distinguish

C. preserve

D. survive

Câu 3: She finally achieved her_______ of visiting the USA.

A. target

B. objective

C. desires

D. ambition

Câu 4: We all regard pollution as a.......... matter to human beings.

A. solemn 

B. great

C. serious 

D. huge

Câu 5: Teachers complain that more of their time is taken up with _______than with teaching.

A. protection

B. administration

C. architecture

D. article

Câu 6: The _______ by UN troops prevented fighting from breaking out.

A. participant

B. intervention

C. joiner

D. contestant