How did geologists decide where one division of the geologic time scale ends and the next begins?

the law of superpostion

events in the history of life on earth, like mass extinctions

they divided the time equally between eras

the placement of fossils throughout the surface layers of earth

i think it's c

the contamination

we are putting to many trash.

a plastic spoon that has a temperature of 78° f is placed into a bowl of soup that has a temperature of 84° f. which of these correctly describes what will happen?

energy as heat moves from the soup to the spoon.

a lot of people sadly don't know the best way to learn is cheating off of your friends or this amazing thing called google