1. Placing iron filings on a magnet can help you see the . A. electric field B. electric current C. gravitational field D. magnetic field

___2. Which of the following does not use Earth’s magnetic field?
A. seeds leaving a plant by motion of the wind
B. honeybees finding their hive
C. birds flying south for the winter
D. trout and salmon swimming upstream

3. Which of the following is a renewable resource?
A. fossil fuels
B. petroleum
C. cotton
D. plastic

4. What is heat energy from Earth’s crust called?
A. nuclear energy
B. thermal energy
C. hydroelectric energy
D. geothermal energy

5. This type of precipitation occurs when air pollutants from the burning of fossil fuels reacts with water in the atmosphere that can pollute water, kill fish and plants and damage soil.
A. polluted rain B. hazardous rain C. acid rain D. distressed rain

6. What causes ozone depletion?
A. CFCs B. factories burning fossil fuels C. smoking D. car exhaust

___7. What traps heat and keeps Earth warm enough to support life?
A. ozone layer
B. greenhouse effect
C. global warming
D. climate change

8. Where do we find the most biodiversity?
A. close to the north pole
B. Canada
C. near the south pole
D. closet to the equator

9. An organism that is at risk of becoming endangered in the near future is
A. extinct species
B. threatened species
C. captive species
D. endangered species

10. A species that is brought to a new area as a result of human actions is
A. a captive species B. an alien species C. an introduced species D. a native species