Answer:
Grey and White Matter.
Explanation:
When looking at an image of trasnverse section of the spinal cord the grey matter is almost butterfly shapped and it has the central canal in the middle. The white matter is surrounding the butterfly shaped, grey matter.
It is a polar molecule I'm pretty sure. And hinataaaa
Cigarette smoking decreases speed in track runner, due to the fact that their lungs have black spots. Making it harder for them to breathe. And harder to breathe causing slowing in speed.
The DNA has to code for a protein and it has to replicate
