I believe the answer you are looking for is Migration. Take birds for example, when it gets cold they go south to where it's warm, and then back again in the summer, they call this migrating. Thus your answer is migration.
Migration is the Correct Answer you would be looking for.
T<span>he definition of a </span>migration<span> is a movement to another place, often of a large group of people or animals. An </span>example<span> of </span>migration<span> is geese flying south for the winter.</span>
A heterogeneous mixture composes of non- uniform components, so the concrete would be the answer, because you can tell the components from one another.
