That they are <span>caused by microorganisms.</span>
Sedimentary, because of the glaciers that once covered Indiana they lithified which is a part of the rock cycle in the sedimentary division.
Natural system is former when various components get grouped together for a particular function
Answer:
<em>A. The air pressure in that section of Earth’s atmosphere decreased.
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Explanation:
In the free air, the density of the air diminishes as the air is warmed. On increasing the pressure, the density also increases. The air is packed. The density increments as pressure increments.
The thickness and density of air decline with the increase of height because of that the surface area of the Earth's climate diminishes with increase in height, along these lines gas particles can spread out.
The density of the air is most minimal at a high rise on a hot day when the pressure of the atmosphere is low.
The algae increase the autotrophy by offering photosynthesis to the fungi in the lichen organism.
A lichen is an organism consisting of a symbiotic association between a fungus (the mycobiont) and algae. The mushroom brings water and mineral salts. The alga produces, by photosynthesis, various organic compounds of which it gives a part to the mushroom.