The answer is D. That is what physics textbooks say.
<span>a)
</span>The milkweed is the primary producer in the
ecosystem. It manufactures food from the abiotic factors in the soil such as
nitrates and water and those in the atmosphere such as carbon-dioxide and
sunlight. The milk weed is then fed on by the caterpillar and a primary
consumer. The caterpillar is then fed on the mocking bird (secondary consumer)
<span>b)
</span>Increased human population growth and their activities
have resulted in the emission of carbon dioxide and other greenhouse gases in
the atmosphere. This has increased the global temperature. This increase of
global temperature increase ocean temperatures causing coral bleaching.
Another example is depletion of water sources
by human activities hence causing drought. Drought reduces the amount of
vegetation growth due to scarcity of water in the soil (due to lowering of the
water table) for plant growth.
Ethanol is a biofuel, which can <span>be fermented from various sources, but in United States, most of Ethanol is made from "Corn"
In short, Your Answer would be Option A
Hope this helps!</span>
If fertilizers enter the St.Johns river they will result in nutrient overload, or eutrophication and harming the ecosystem of the river. The river will exceed its assimilative capacity for nitrogen and phosphorus. this will <span>deplete oxygen in the water needed by fish and reduce light that is essential to submerged vegetation. </span>
