What part of the ocean contains the most life

The layers of earth are based on what two sets of characteristics?

Which of the following can scientists estimate geologic time? a. observing rock sequences b. radiometric dating c. comparing fossils d. all of these

Which phrases describe oxygen's roles in earth’s atmosphere? check all that apply. allows fuels to burn forms clouds that produce rain is the gas that animals breathe is used by plants to produce food forms ozone that absorbs the sun's harmful rays