Câu hỏi: 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

Câu 1: Having finished his tem paper before the deadline, it was delivered to professor before the class.

A. having finished

B. before

C. it was delivered

D. before

Câu 2: It is very difficult for her to prevent him for smoking in her house.

A. very

B. for 

C. prevent 

D. for smoking

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

A. worst

B. the

C. before

D. tried

Câu 6: Tom said that he was trying to carry out some campaigns to protect environment and will encourage others to do so.

A. he was trying

B. some

C. campaigns

D. will