People use a lot of vehicles. The air is polluted.

People use a lot of vehicles. The air is polluted.
A. If people don’t use too many vehicles, the air won’t be polluted.
B. If people won’t use too many vehicles, the air don’t be polluted.
C. If people wouldn’t use too many vehicles, the air didn’t be polluted.
D. If people didn’t use too many vehicles, the air wouldn’t be polluted.
 
Đáp án: D
Giải thích: Câu điều kiện loại 2: If + S +Ved, S would V
Dịch: Nếu con người không dùng quá nhiều phương tiện giao thông, không khí sẽ không bị ô nhiễm