Câu hỏi: The aircraft carrier is indispensable in naval operations against sea or shore based enemies.

A. unique

B. novel

C. exotic

D. vital

Câu 1: The famous racehorse Secretariat had to be destroyed because of a painful, incurable hoof disease.

A. disabling

B. vexatious

C. dangerous

D. irreparable

Câu 2: He was asked to account for his presence at the scene of crime.

A. complain

B. exchange

C. explain

D. arrange

Câu 3: Hypertension is one of the most widespread and potential dangerous diseases.

A. colossal

B. popular

C. common

D. scattered

Câu 4: The raccoon is a nocturnal animal.

A. harmless

B. night

C. marsupial

D. diurnal

Câu 5: In the United States, a party can nominate a single candidate for office.

A. refuse

B. keep

C. change

D. appoint

Câu 6: We watched as the plane disappeared behind the clouds.

A. melted

B. escaped

C. vanished 

D. perished