The answer is letter c.
It can be both natural and human source of pollution. There are times when the intense heat can
trigger a brush fire and can expand depending on how strong the wind
blows. It can be caused by humans. it could due to carelessness of people leaving
flammable materials unchecked. Or using too much fuel that when lit would cause
a brush fire that would expand into a wildfires. The smoke from it pollutes the air.
A is possibly your best option, even as themes can be impacted by setting in many other ways......theme is the main and idea of the piece of literature and a theme can also symbolize a primary conflict.
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The sentence that begins 'In the dull...'
Tense tones are usually used.
