The answer is all of the because
This qualifying core is an area with a population density of at least 1,000 people per square mile that contains at least 50 percent of Page 8 12-8 Urban and Rural Classifications the place's total population and is contiguous with other qualifying urbanized territory that also meets the population density criterion.
It's called chemical reaction.
(I'm not real sure)
Answer:
having traits that help a single organism survive
