Which pull factor is the most common reason why developed countries draw migrants from developing countries?

2. x2 + 8x + 12 = 0 to prove: x = -6 or x = -2

Ansradar; im guessing here; good luck : )

They contributed many things, but here are some examples:

1) democracy - democracy as a political system was first implemented in ancient athens
2) some advances in mathematics - such as the pythagoras' law
3) the script - the roman script was adopted from ancient greek.