Photovoltaic cells and hydrogen fuel cells share which of the following advantages? I. No emission of air pollutants
II. Abundance of resource
III. Inexpensive compared to other resources

A. I only
B. II only
C. I and II only
D. I, II, and III

An easy way to calculate the amount of energy available at each level is to what?

Explain how organisms could be harmed by high levels of salt from roadways?

Migration is a. the movement of organisms from a native location to a foreign location b. the movement of organisms from a foreign location to a native location the movement of organisms from their water supply to their food supply d. the seasonal movement of organisms between locations c. select the best answer from above