7. Why do some people suggest that we not must rely on nonrenewable resources? a. Each resource cannot affect the environment.
b. They make large amounts of pollution as they are used. c. Nonrenewable resources will probably run out in the future. d. Both b and c

8. How has people’s use of energy change over time? a. People have always used about the same amount of energy, regardless of how many resources have been available. b. People have been using more and more energy, even though some resources have begun to run out. c. People have been using less and less energy because some resources have begun to run out. d. When large amounts of energy resources are available, people use more energy. When fewer resources are available people use less energy

9. Why is the sun considered as the ultimate energy source?
a. The sun is the center of the solar system.
b. The sun is limited in the amount of energy released daily.
c. The sun rises and sets each day as seen from earth.
d. The sun provides energy for water cycle and plants.

10.Why is it important to save to save energy in our daily lives?
a. So that people can waste energy.
b. We need to burn more fossil fuels.
c. We need to protect our environment for the future.
d. We save electricity because it is better to see in the dark.​