Mark the letter A, B, C, or D to indicate the correct answer to each of the following sentences.

Câu hỏi

We should reduce the use of coal, which is the dirtiest fuel and biggest ________ of CO2 emissions.

A. resource

B. source

C. origin

D. base

Đáp án
B. source

Câu hỏi thuộc Bài tập:

UNIT 5: GLOBAL WARMING - VOCABULARY - Tiếng Anh 11 Global Success