What are two steps that can be taken in order to not run out of resources with a growing population?

Why are mangrove swamps an important part of the ecosystem of west africa?

Distance that lewis and clark traveled from st. louis to ft. clatsop near the pacific ocean.

What's erosion? a. the breakdown of rock into smaller pieces b. the removal of weathered products from rock c. a change in rock resulting from exposure to water d. a chemical change in rock that weakens it