I would say that active transport is the answer because it's from LOW concentration to HIGH concentrations, so it's going against the concentration gradients.
I think the correct answer from the choices listed above is the first option. The density of a mineral is the ratio of a mineral's mass to its volume. Density<span> is a measure of the mass of a certain volume of the sample. Hope this answers the question.</span>
Expository writing is explaining things in clear, logical steps, whereas narrative writing is telling a story, either fiction for enjoyment or an educational or exemplary story for an essay.
