What is the largest source of sulfur dioxide air pollution?
a.
transportation
b.
the greenhouse effect
c.
burning fossil fuels in vehicles, power stations, and factories
d.
construction, agriculture, and unpaved roads

c. burning fossil fuels in vehicles, power stations, and factories

Explanation:

The sulfur dioxide is one of the biggest polluters of the atmosphere. The main sources of this pollution are from burning the fossil fuels such as coal, oil, and natural gas, where the sulfur dioxide is released as a waste product from their burning. This gas is actually very toxic, and it is the main cause why there's an ever increasing occurrence of acid rains. The sulfur dioxide manages to mix with the water vapor in the formation of the clouds, and when the rain falls it contains sulfur dioxide as well. This causes lot of damage to plants, erodes the infrastructure, as well as harming the respiratory systems of the animals and the humans.

c

Explanation:

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.