1. It is a combination of different gaseous elements and other airborne solid particles like dust,smoke,oil and heavy bits of metals like aluminum and lead.
A. photochemical smog
B. industrial smog
C. ultra-violet rays
D. industrial pollution

2. photochemical smog has a brown atmosphere which comes from what compound?
A. nitric oxide
B. hydrogen oxide
C. Corbon oxide
D. aluminum oxide

3. An agreement between different governments to reduce emissions.
A. greenhouse gas emissions protocol
B. Montreal protocol
C. ozone-depleting protocol
D. Montreal protocol

Help me..​