Answer: Avoid spilling of chemicals
Explanation:
The chemicals should be kept in air tight containers in order so that they cannot get spill over each other.
Cross contamination takes place when a different type of substance comes in contact with the different kind of substance.
The chemicals should be kept in a way that it does not comes in contact with the different one and get spoiled.
My guess is A, but I don't know for sure.
They both control the backbone. I think. The Respiratory system
Is my favorite
Answer:
You could check the Google for that
If your body is lacking a substance like water or salt it will reabsorb some of it,