Which question cannot be answered through making measurements? A. Which species in a national park do wolves hunt?
B. How would reintroducing wolves into a national park affect the
deer population there?
C. What is the birthrate for wolves in their natural habitats?
D. Should wolves be reintroduced into national parks?

Hydroelectricity provides about 7 percent of the electricity generated in the united states. (a) explain how a hydroelectric power plant converts energy stored in water into electricity. (b) identify two factors that determine the amount of electricity that can be generated by an individual hydroelectricity power plant. (c) describe the two main types of land-based hydroelectric power plants. (d) describe two economic advantages and two environmental disadvantages of hydroelectricity.