An estuary is where salt water and fresh water meet. Estuaries are usually found at the edge of the coast, where the ocean water, or salty water, meets river, lake, any fresh water source, water.
A tributary is something completely different. It is a, usually smaller than the main river or lake, river/stream stemming off a bigger river or lake, or flowing into that river or lake.
3. Helps protect life on earth
Answer:
The sun, our star, will eventually die and become a white dwarf.
Explanation:
When a star dies it goes through a process in which it is called "The lifecycle of a star."
If the sun were to go theough this process and die out, it would eventually reach to the point it can either be a white or black dwarf, but there is more of a possibillity of it becoming a white dwarf than a black dwarf.
