What was the basic political unit of sumer

On this map of the united states the letter h indicates high pressure and the letter l indicates low pressure . select the black arrow that accurately shows the direction of the wind.

Informatii despre riul nistru dup algoritmul pozitia pe continent originea denumirii lungimea izvorul gura de varsare afluentii directia riului caracterul cursului activitatea de model are regimul. de inghet variatia nivelului so volu! mul de apei tipul de alimentatie importantanta pentru om unitatile de relief strabatute caderea riului

Ascientist makes a map using gis. one layer is an aerial photograph of farmland. other layers show water level changes and how crop cover has changed over time. what might the scientist be studying?