To accept the evidence presented in the Familial Hypothesis one must assume that all members of a population sharing the
same gene pool have:
a. a varied family history.
b. a common family history.
c. a history of high risk for heart disease.
da history of low risk for heart disease.

when it is at an intermediate population density

all these collisions do one thing, and that thing is explained in the last option. when dusst, rocks and ice collide, they harden and form giant layers of rocks or hard ice.

d)   to harden materials to form different parts of earth’s layers

hope it ,

bioteacher101