How did the geography ancient Greece differ from that of River Valley Civilizations?

Visit the kindly folks at Google.com, enter the thread title ( or enter apart, first enter GREECE then enter RIVER VALLEY CIVILIZATIoNS (Tigris-Euphrates, Huang-He, Nile, Indus) and read all about it, Greece, its terrain, and then the 4 greatest river valley civs. and their terrain.
(maybe glance at a map)
Read, learn, write the paper, submit the paper.

This you will get started

http://landmarkhs.org/news/archives/socialstudies/rivervalleys/

Generally, Greece is very mountainous with relatively small arable flatlands, whereas the river valleys are, or were, large flatlands which because of the annual flooding of the rivers had extremely fertile soils.

The thrust of the question is, or it ought to be, why civilization arose in Greece in conditions so radically different than the Nile valley, the valley of Mesopotamia and the Indus valley. The answer is that the Greeks borrowed civilization from existing civilizations of the eastern Mediterranean.