According to Carson, Earth before human beings
was a place that
had some hazardous elements
was completely free of pollutants or harmful
elements
quickly removed any hazards from the
environment through natural processes
DONE

Pollution is the introduction of harmful materials into the environment. These harmful materials are called pollutants. Pollutants can be natural, such as volcanic ash. They can also be created by human activity, such as trash or runoff produced by factories. Pollutants damage the quality of air, water, and land.

Explanation:

four sitting presidents have been assassinated while in office but the first was abraham lincoln,