BIOGAS HELPS SOLVE THE PROBLEM OF INDOOR ___________.A. NOISE POLL...

3. - File thứ 1: de_thi_anh_7_232201910
File thứ 1: de_thi_anh_7_232201910

3. Biogas helps solve the problem of indoor ___________.

A. noise pollution

B. air pollution

C. water pollution

D. soil pollution