The biogeochemical cycle that most affects the earth's temperature is the

water cycle
nitrogen cycle
carbon-oxygen cycle
carbon cycle

The oxidizing agent our bodies use to obtain energy from food is oxygen (from the air). if you breathe 15 times a minute (at rest), taking in and exhaling 0.5 l of air with each breath, what volume of air do you breathe each day? air is 21% oxygen by volume. what volume of oxygen do you breathe each day?

Give the biological term for: structures that display characteristics of living organisms only within living cells

Which of the following is a consequence of urban heat islands? increased precipitation downwind of the city? increased precipitation upwind of the city? decreased winds within the city? increased winds within the city?