Which of the following is not considered an aspect of environmental health a) control of drinking water b) contral of hazardous chemicals c) control of sexually transmitted diseases d) control of public sanitation

What percentage of light hits earth's surface directly?

Some tools have graduations to show multiple measurements. for example, a ruler may have graduations for both millimeters and centimeters. when measuring the length of an earthworm, which graduations would allow for the most accurate measurement? millimeters centimeters decimeters meters

Tropical rain forests support more species per unit area than any other terrestrial ecosystem. what is one way rain forests are important to the health of the biosphere?