Câu hỏi: The world is becoming more industrialized and the number of animal species that have become extinct have increased.

A. industrialized

B. species

C. extinct 

D. have

Câu 1: It is very difficult for her to prevent him for smoking in her house.

A. very

B. for 

C. prevent 

D. for smoking

Câu 2: My sister told me that she had met my teacher at the supermarket yesterday.

A. My sister told

B. had met

C. at the supermarket 

D. yesterday

Câu 3: If they took their language lesson seriously, they would be able to communicate with the locals now.

A. took

B. seriously

C.  would be

D. with the locals

Câu 4: My elder sisters, both of them were doctors, said they were too busy to pick me up.

A. elder

B. both of them

C. too busy 

D. to pick

Câu 5: If you take the train, it would be much more convenient.

A. if

B. the train

C. would be

D. much

Câu 6: Proteins are made up of folded irregularly chains, the links of which are amino acids.

A. made up of

B. folded irregularly

C. the links

D. which