Câu hỏi: 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 1: Henry David Thoreau was an American writer who is remembered for his faith in religious significance of the nature.

A. an

B. is

C. for

D. the nature

Câu 2: 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 3: 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 4: The bones of the elderly are more prone to fractures than of young people.

A. the elderly 

B. more

C. to

D. of

Câu 5: 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 6: A smile can be observed, described, and reliably identify, it can also be elicited and manipulated under experimental conditions.

A. identify

B. experimental

C. can also

D. A smile