PLZ HELP ME PLZ Why was irrigation important to Sumer?

A.) It led to the invention of the sail.
B.) It helped create food surpluses.
C.) It led to trade with other city-states.
D.) It moved water from mountains to city-states.

Me! why was marbury v. madison such an important case? a. it confirmed that the supreme court was more powerful than congress but less powerful than the president b. it confirmed the authority of the supreme court to review a law in to determine whether or not that law is constitutional. c. it confirmed the authority of congress to increase or decrease the power of the supreme court. d. it gave the supreme court the power to confirm federal judges.