The sum of kinetic energy and potential energy within a system is called a) thermal energy. b) chemical energy. c) electrical energy. d) mechanical energy.

Coral reefs support more species per unit area than any other marine environment on earth. what is one way coral reefs are important to the health of the biosphere

Why are scientists concerned about the depletion of the ozone levels in the stratosphere?

What function does a limb serve in each animal how are the limb bones of the four animal similar based on the similarities what can be inferred about the evolution of the poor animals