The function of the digestive system is to C. To break down food into nutrients.
Answer:
B.air density
Explanation:
Updraft and downdraft is the upward and downward movement of air.
It caused by differences in air densities. There could be differences in air current due to the heat that occur in the ground during the day time which makes air above more warmer than the air below. The air above is less dense as it rises above it becomes cool.
It also occur when air current moves over mountains.
