Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.

Câu hỏi

We can help the environment by ................ the lights when we leave a room.

A. turning on

B. turning off

C. to turn on

D. to turn off

Đáp án
B. turning off

Câu hỏi thuộc Bài tập:

TN-PART1-20KEY