C. It requires active transport because the use of energy is necessary, the natural and opposite flow to this, would be from high to low concentration that requires little to no energy (i.e passive diffusion).
All the chemical processes used to build up or break down materials are called an organism's
To divide reproductive cells
The answer is B, because layers mix better at the poles.
Answer: N-14
Explanation: When C-14 undergoes radioactive decay, atoms of N-14 are formed
