Can some me this is an assignment

as resources become scarce because of population growth, the growth decreases after few years due to lack of resources and food.

sound moves fastest in solids because the molecules are tightly packed and it allows sound to vibrate

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