Why does a mixture of oil and water behave differently from a mixture of milk and water?

The answer for #3 is c but i don't know why

What causes different colors to appear in the sky? the absorption of light by air molecules the reflection of light by bodies of water the greenhouse effect in earth's atmosphere the scattering and reflection of light by dust particles

Two nails have identical sizes and shapes. in one nail, 20 percent of the domains are lined up. in the other nail, 80 percent of the domains are lined up. which has stronger magnetic force? first answer gets brainliest!