How do unconformities represent gaps in geologic time?

Answergovernment control over all imports and exports;

I'm hella smart but i dont know that

Nswer iceland is one of the most active volcanic regions on earth

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.