HOC24
Lớp học
Môn học
Chủ đề / Chương
Bài học
chọn B
Mark the letter A, B, C or D on your answer sheet to indicate the underlinedpart that needs correction in each of the following questions from 21 to 23.
Air pollution, together with littering, have been causing many problems in our large, industrial cities in the last few years.
A. with
B. in our large
C. many
D. have been