Why isn't the atmosphere a closed system? 1.Closed systems only exist in theory.
2.Closed systems are only for liquids, not gases.
3.The laws of physics do not apply to the atmosphere.
4.Gases from Earth escape from the higher realms of the atmosphere.

Which of the following would involve looking at different structures of organisms and comparing how similar they are? a. vestigial structuresb. radiometric datingc. homologous structures

The scientific method is limited to investigating physical phenomena that are which of the following? select all that apply. observable repeatable falsifiable unique measurable

Which of these internal feedback reactions does not need your brain? oa. your leg jumping when it is hit by a reflex hammer b. your deeper breathing when you need more oxygen c. your body temperature rising when you have an infection d. your heart beating faster when you are in danger