Which of the following statements is true? groundwater is not part of the water cycle. most of earths water is freshwater. refining oil pollutes in the air with nitrogen dioxide. thermal pollution is the main disadvantage of hydroelectric power.

The correct answer is - Thermal pollution is the main disadvantage of hydroelectric power.

The hydroelectric power is gained in the dams that are set on the rivers. Its main disadvantage is the thermal pollution. Even though some people do not take this kind of pollution seriously because there's no physical waste, it is a very dangerous one for the local ecosystems.

The thermal pollution in essence is the warming up of the waters where the dam is created for the production of hydroelectric power. The reason why the water warms up is because it is becoming much more static because of the dam.

The organisms that live there are adapted to certain temperature of the water, so a change like that usually results in the dying off of some species, though others may prosper. Which ever way it is looked at it, it manages to disrupt and change the local ecosystem.

the answer is "a.) well–developed vascular system."

explanation:

the correct answer is b