Covalent compounds often melts easily because

thinking it would be physical characteristics

the correct answer is sex-linked recessive.

i just took the test

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