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.

Arguably one of the most important inventions of the 20th century was a) the transistor. b) air conditioning. c) the vacuum cleaner. d) radio broadcasting.

Which of following most accurately describes china today?

What is the evidence that depression can be linked to genetic as well as environmental factors? a. all individuals in similar stressful environments do not experience depression. b. all individuals with the gene variation tied to depression do not experience depression. c. individuals with a combination of environmental stress and gene variation are more likely to experience depression d. all of the above select the best answer from the choices provided оа 0 0 0