Which statement is correct with respect to gross primary productivity?
A.
It is the total amount of energy produced by plants.
B.
It is the amount of energy used by plants for respiration.
C.
It is the amount of carbon dioxide that the plants release.

Describe the change in phase and temperature as water moves from the oceans to the atmosphere and then returns to earth again as rain. a) evaporation : temperature increases; condensation : temperature decreases; precipitation (rain) : temperature decreases b) evaporation : temperature increases; condensation : temperature decreases; precipitation (rain) : temperature increases c) evaporation : temperature decreases; condensation : temperature decreases; precipitation (rain) : temperature decreases d) evaporation : temperature increases; condensation : temperature increases; precipitation (rain) : temperature decreases