River-valley civilizations developed in Sumer, Egypt, China, and the Indus River Valley. After following the procedures in the Planning a Compare and Contrast Essay worksheet, write an essay comparing and contrasting these civilizations.

How do ocean currents affect temperature? check all that apply. they carry cold water from the poles to the equator and cool air over land. they flow north and then south below the equator. they flow south and then north above the equator. they move warm water from the equator to the poles and heat air over land. they move east to west and create prevailing winds. they move west to east and create seasonal winds.