Answer:
according to me butter is not a oil. But its good to have it as it is formed from milk!
Answer:
A concentration gradient occurs when the concentration of particles is higher in one area than another. In passive transport, particles will diffuse down a concentration gradient, from areas of higher concentration to areas of lower concentration, until they are evenly spaced.
well hope this help at least (good night)
It's B. 10 to 20 percent.
