Câu 21. Hundreds of years ago _____________.
A. the environment was polluted as much as it is today. C. air was polluted badly
B. people knew nothing about environmental pollution. D. people was faced with pollution.
Bạn đang xem câu 21. - Đề thi thử bài Tổ hợp vào THPT huyện Yên Lạc lần 2 ngày 13/6/2020
