Among the subsystems which is composed of mixture of gases that surrounds the earth

Average annual precipitation and are the two major features that define the biomes on earth.

How does the molecular clock work? a. it analyzes the brain functionality of two different species.b. it examines and compares the physical characteristics of two different species.c. it illustrates relationships between two different species.d. it compares the number of mutations that exist in the dna of two different species.

Environmental science are unconsidered with methods to preserve natural resourcesa.trueb.false