Câu hỏi: 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

Câu 1: 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 2: 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 3: It is recommended that people to take regular exercise.

A. recommended

B. people

C. to take

D. exercise

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

A. very

B. for 

C. prevent 

D. for smoking

Câu 6: If you take the train, it would be much more convenient.

A. if

B. the train

C. would be

D. much