Câu hỏi: Human beings are ________ greatest threat to survival of endangered species.

A. Ø

B. an

C. the

D. a

Câu 1: The view is great, _______?

A. isn't it

B. was it

C. doesn't it

D. did it

Câu 2: The students got the librarian_________ books for them.

A. buying

B. to buy

C. buy

D. bought

Câu 3: _________, we couldn’t make out the gist of the passage.

A. Due to Romeo’s carefully explanations

B. Though carefully explained by Romeo

C. Carefully as Romeo explained

D. As Romeo carefully explained

Câu 4: It was hot, _________ I turned on the conditioner.

A. however

B. but

C. because

D. so

Câu 5: They_________ Ho Chi Minh City last summer.

A. visit

B. will visit

C. have visit

D. visited

Câu 6: In an essay writing in 1779, Judith Sargeant Murray promoted the cause of women's education.

A. the cause of

B. writing

C. In an essay

D. women's education