Câu hỏi: 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

Câu 1: The bones of the elderly are more prone to fractures than of young people.

A. the elderly 

B. more

C. to

D. of

Câu 2: My teacher is very strict and he always makes us to finish all the exercises before leaving school.

A. is

B. strict

C. to finish

D. leaving school

Câu 3: If you take the train, it would be much more convenient.

A. if

B. the train

C. would be

D. much

Câu 4: Each of the members of the group were made to write a report every week.

A. were

B. members

C. to write

D. week

Câu 5: 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 6: My father asked me where had I gone the night before.

A. the

B. asked me

C. had I

D. before