please give me answer

Answers
Answer:
a/ air pollutants
b/ oxygen
c/ atmosphere
d/ gills
e/ combustion
A. An Undesirable constituent of Air:
Air pollutants pollute the air. The polluted air harms living organisms. Some of the include Chloroflurocarbons, Carbon Monoxide, Smog, etc.
B. The constituent of air that helps in burning:
Oxygen helps in burning. With lacking of oxygen, combustion doesn't takes place.
C. The thick layer of air surrounding the Earth:
Atmosphere is a thick layer of air. Its major components are Oxygen and Nitrogen. This helps us in many ways.
D. Fishes take in dissolved oxygen through this organ:
Gills take oxygen present in water. Then, the oxygen helps them in providing energy to perform various activities.
E. Carbon Dioxide doesn't support this process:
It doesn't support combustion. This main gas required for combustion is Oxygen.