Drought and leaching have contributed to the process of a major environmental challenge in africa

This is a 2017 topographic map of puerto rico in the united states, and i'm sorry that people there have suffered such a disaster. i want to ask, what do the yellow dots and areas represent on this graph? and the blue area and the little blue circle, and the little blue sign that looks like a signal tower, what do they stand for?

Plz hury on a timer which statements explain what happens at deep-ocean trenches? check all that apply. crust is formed. mountains are formed. seafloor spreading occurs. crust becomes molten rock. denser plates slide under lighter plates.

These issues present challenges for regional urban areas. select all that apply. -housing availability -inadequate services -pollution -reduced population -rural migration