A the species tends to form social groups
More people move to mdcs bc of pull factors. they leave ldcs bc of push factors.
I believe the answer is d.
P represents heating and Q represent cooling.
this is because when you start from a liquid and turn to a gas the particles move faster making them farther apart, causing a gas. the opposite happens when you go from a liquid to a solid. the partials move closer together causing a solid to form. :)
