Neurons are to neurotransmitters as endocrine glands are to:

mountains can affect the climate of nearby lands. in some areas, mountains block rain, so that one side of a mountain range may be rainy and the other side may be a desert. much of airborne moisture falls as rain on the windward side of mountains.

explanation:

the dark variety, as they are not visible on the dark tree barks

explanation:

2%? i tried finding the exact sorry if it's not 100% correct ; -;