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

A. Ø

B. an

C. the

D. a

Câu 1: Mike came across his old friend - Maria while he _______ along the street.

A. had walked

B. would walk

C. was walking

D. walked

Câu 2: If you eat too much, you _________ the price by putting on weight.

A. will pay

B. paid

C. would pay

D. were paying

Câu 3: It was hot, _________ I turned on the conditioner.

A. however

B. but

C. because

D. so

Câu 4: If I _______ just one year younger, I would be eligible for the scholarship.

A. am

B. will be

C. would be

D. were

Câu 5: We _________ already ________ Huong Pagoda.

A. were…seeing

B. have…seen

C. are…seeing

D. will…see

Câu 6: The students got the librarian_________ books for them.

A. buying

B. to buy

C. buy

D. bought