Window cleaners that work the top floors of high-rise office buildings are, on average, paid approximately 30 percent more an hour than those that clean windows on the bottom floor. this is an example of

The answer is compensating wage differentials.

Explanation:

The term refers to an extra amount of money that should be offered to a worker in order to perform a difficult, dangerous or undisirable job. On the other hand, it's also possible to offer a negative differential for jobs that may be desirable or easy to perform (they get paid less).

Some factors to consider are risk of injury or risk of future unemployment.

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.