What is a republic?how did the roman republic compare to Greek democracy?

In contrast to Greek democracy, the Roman republic had a more complex institutional arrangement. Instead of a set of institutions through which one single group exercised power, the Roman republic contained multiple institutions that allowed both the few and the many to take part in political rule.

Sorry if wrong

in 342 bc j._c. egypt fell into the hands of the persians, under the reign of nectanebo ii

greek city-states unite in a revolt against the persian empire at the beginning of the fifth century bc. j.-c  

from the year 660 or 659 bc ad, cyrus preached the revolt against the medes to deliver the persians.