A I think sorry if your wrong :( .
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.
Separate Layer it's part of the "Atmosphere layers"
It was a old network of trade routes that were for centuries central to cultural interaction first through areas of Eurasia<span> connecting the </span>East<span> and </span>West<span> and all the way from the Korean peninsula </span><span>and Japan </span><span>to the Mediterranean Sea</span>
Answer is E because dat was there biggest struggle in tho times
