What enzymes has an optimum working pH of 1.5?

What does natural resource management aim at ?

Resperation is a way to release carbon back into the atmosphere

The greenhouse effect a. something that has occurred for millions of years b. an unnatural phenomenon caused by humans that maintains earths temperature range. c. the results of the differences in the angle of the suns rays d. an unnatural phenomenon that causes heat energy to be radiated back into the atmosphere