Câu hỏi: Let’s _________ water by turning off tapes when not using.

A. save

B. to save

C. saving

D. saved

Câu 1: A hydroelectric dam ______________ in this area now.

A. is building

B. is being built

C. build

D. was built

Câu 2: The two children blamed each other ...... the window.

A. to break

B. breaking

C. for breaking

D. having broken

Câu 3: What about ___________ the solution together this afternoon?

A. find

B. finding

C. to find

D. to finding

Câu 4: After she ________ hospital, she had a long holiday.

A. leaves

B. is leaving

C. had left

D. has left

Câu 5: The campaign will hopefully ensure the survival ...... the tiger.

A. of

B. for

C. to

D. on

Câu 6: People are destroying the air by adding ...... to it.

A. pollutants

B. polluters

C. pollution

D. polluted