What did city-states in Sumer have in common? They shared the same laws.
They were centers of trade.
They were all ruled by one king.
They were home to millions of people.

i believe

clean air is essential for health and survival

clean air provides nitrogen gas for plant respiration

clean air supplies oxygen that enables living organisms to breathe

hope this

i am brianly

sorry if this doesn't

answer; sex,attention,sleep,thirst, and hunger and many other vitals;