What percentage of known marine plant and animal life do coral reefs contain?
a. 25%
b. 30%
c. 35%
d. 40%

People keep spending additional units of a particular resource on a want until their marginal benefit is  decreasing withgreater thanless thannot affected by  their marginal cost.

Based on current rates the earths human population is expected to grow how much by 2050

What can happen to solar radiation when it enters earth’s atmosphere? check all that apply. it is absorbed by earth. it is reflected by clouds. it is reflected by glacial ice. it is condensed into visible light. it is amplified by water molecules.