If many people in a community get flu shots, the whole community benefits, including those who did not get flu shots. Therefore, not enough people may decide to get the shots. This is one illustration of .

Demand side market failure:

Explanation:Demand side market failure occurs when the business fails to charge the consumer for a particular product or service .

For example fire works can be enjoyed by everyone , even those who didn't buy them because it is impossible to do so.

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.