The answers are
1. nitrogenous
2. acid-base
3. fluid
<span>The answer is a certain required chemicals must be actively
transported. Blood brain barrier is a
selective membrane that separates blood circulating from the brain and the
fluid of extracellular in the central nervous system. This is also called a
filtering mechanism, the capillaries that carry blood to the brain and spinal
cord tissue blocking the path way of the certain substance.</span>
<span>Living things are made of cells.Living things obtain and use energy.Living things grow and develop.Living things reproduce.Living things respond to their environment.<span>Living things adapt to their environment.</span></span>
Answer:
b) natural variation w/in a species
Explanation:
All the answer you put are evidence of evolution also I have done this before.
I’m pretty sure it’s species :)
