I could hardly breathe because of the thick cloud smoke.
I could hardly breathe because of the thick cloud ___________ smoke.
A. of
B. in
C. on
D. at
Đáp án A
I could hardly breathe because of the thick cloud of smoke. – Tôi không thể thở nổi vì đám khói dày đặc. - cloud of smoke: đám khói