Using what you know about the chemical makeup of stomach contents and the control of food moving through the gi tract, provide a reason some people get heartburn. what is actually happening to cause this burning sensation in the chest?

9. wind power creates pollution. water air soil noise

Consider the model of the oxygen cycle on earth. the majority of earth's oxygen reservoirs are found in the a) atmosphere. b) biosphere. c) hydrosphere. d) lithosphere.

Which of the following describes a boom period? a. as one population increases, another population decreases. b. as one population increases, the other population also increases. c. as one population decreases, another population increases. d. as one population decreases, another population also decreases