The word those in paragraph 2 refers to__________.
A.A.
bronchitis and asthma
B.B.
carbon dioxide and nitrogen oxides
C.C.
dangerous gases
D.D.
respiratory diseases
Đáp án và lời giải
Đáp án:C
Lời giải:
Dẫn chứng: Dangerous gases such as carbon dioxide and nitrogen oxides cause respiratory diseases, for instant, bronchitis and asthma. Those are also proved ....