Question

What impact did nearness to the sea have on the development of Greece?

Answer 1

The seas linked different parts of Greece, as well as the surrounding world, together.

Answer 2

Greece's economy was mainly based off the sea.
Example: fishing, whaling, trade was usually by boat, invasions were mainly from boats to, etc.
Greece also was split from mountains, and except for the occasional trade route, they mainly traveled from one city state to the next by boat. (depending on how much time they have)

hope this helps :D