The main function of the human digestive system is to
OPTIONS:
- break down foods for absorption into the blood
- exchange oxygen and carbon dioxide in the lungs
- release energy from sugars within the cells
- carry nutrients to all parts of the body

break down foods for absorption into the blood

The longitude of a location determines which time zone it is in. Different time zones are the result of
OPTIONS:
- Earth's rotation
- Earth's revolution
- the Moon's rotation
- the Moon's revolution

Earth's rotation

Some of Earth's water is stored underground in porous rock formations known as aquifers. Which of these could use up groundwater in aquifers?
OPTIONS:
- abundant rain in the Ozarks
- excessive pumping from wells
- dams on the lower Mississippi
- community water conservation
excessive pumping from wells