A shell is considered as biotic (living) because it is a hard, rigid covering of many animals such as snail, sepia, pila, turtles, sea urchins. A shell is protective outer layer of these soft bodied animals.
D, a net transfer of energy
Answer:
Substance B is a group of hydroxide ions.
Explanation:
He could race multiple cars with different weight added on them and do multiple races (just to be sure) and see if his theory was correct, if not he should right down what he has learned from his experience! :D
-You'll never learn if u don't try ;)