Answer:
most likely the water was evaporated by the sun
Explanation: Evaporation is the process in the water cycle when water particles heat up and turn from a liquid into a gas.
Answer:
The barrier functions to regulate the chemical composition of the extracellular fluid surrounding the brain cells.
Explanation:
Blood-brain barrier
It is a very selective semipermeable membrane , hence allow some specific substance to pass via it . This barrier separates the extracellular fluid in the central nervous system and the circulating blood from the brain .
<u>The barrier is composed of the endothelial cells .</u>
Passive diffusion is shown in this system , and allows molecules like the water , glucose , amino acid to pass .
It regulates the chemical composition of the fluid of brain cell .
Answer:
this is my lazy guess but: human activity, differences in emitted energy from earth, and natural fluctuations. BUT DONT TRUST ME LOOK IT UP IM NOT SMART
