How is the Amazon River a barrier? Check all that apply.

A. It runs 6,400 kilometers, splitting the continent.

B. Tributaries are long and fanned out, splitting up the land.

c. It's hard to reach through the rain forest.

D. The water is often polluted with mercury.

The layers of earth are based on what two sets of characteristics?

People make choices about how to use resources.

17. the soil erosion pictured here is the result of what? a. harvesting renewable resources at a rate greater than the sustainable yield b. a mudslide caused by excessive rains c. harvesting renewable resources at a rate lower than the sustainable yield d. the transition between geologic eras and eons