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: 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 2: Although most species of small birds gather in groups at feeders provided by bird-watchers, the bright red cardinals usually appears alone or with its mate.

A. at

B. cardinals

C. or

D. its

Câu 3: 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 4: The most visible remind of the close relationship between the United States and France is the famous Statue of Liberty, which stands in New York habor.

A. remind

B. between

C. is

D. which

Câu 5: Students suppose to read all the questions carefully and find out the answers to them.

A. suppose

B. all the

C. all the questions

D. them

Câu 6: The harder he tried, the worst he danced before the large audience.

A. worst

B. the

C. before

D. tried