Which layer of the earth’s atmosphere do we live in

   Humans live in the layer of the atmosphere referred to as the troposphere. (Most of the mass of the atmosphere can be found in the troposphere.)

i believe it would cause an increase of percipitation, though i could be wrong. so i would say b is the answer.

blue stars have the highest surface temp

stellar distances are usually expressed in light-years

the measure of a star's brightness is called magnitude

hope this !