Which phrase describes estuaries?
-are made of fresh water only
-are areas where rivers flow into lakes
-are homes to unique plants and animals
-are places where all of Virginia's water drains

The correct answer is "are homes to unique plants and animals".

Explanation:

Estuaries are areas of water that provide environmental and chemical characteristics that are unique because of their location where rivers meet the ocean or another large bodies of water. Estuaries are homes to unique plants and animals that have adapted to variations in water salinity as well as the fall and down of tides. Some plants and animals that live in estuaries are oyster reefs, kelp forests, submerged aquatic vegetation, as well as species of crabs, marine worms, raccoons, opossums and many others.

c. heat from the poles back down towards the equator.