Chapter Thirteen

4. Answer: a. The earth's wobble is made less predictable by the fact that it is affected gravitationally by the gas giant planets of Jupiter and Saturn. The cycle of this effect is 112,000 years.

5. Answer: b. Each of these is a positive reason or benefit from having a rainy season. One adverse effect is that the incidence of many tropical diseases that are mosquito-borne is increased during this season.

6. Answer: c. The definition of a monsoon season is that the winds shift markedly during monsoons, usually seen in Southeast Asia or other parts of

Asia.

7. Answer: a. Each of these drives the density of the water in our oceans. The exception is surface winds, which do not have a direct effect but perhaps a secondary effect on this property of water.

8. Answer: d. Cold water travels away from the poles in the deeper waters, while warm water comes from the equators to the poles in the surface water.

9. Answer: d. Carbon dioxide is the major contributor to the global warming we are seeing as it is the most damaging greenhouse gas.

10. Answer: a. The temperatures and sea levels on earth will continue to rise by 2100, even if we curb our fossil fuel use immediately.

CHAPTER THIRTEEN

1. Answer: d. Almost all air pollution diseases due to particulate matter are lungrelated, causing these diseases. Eczema of the skin would be less likely from particulate matter.

2. Answer: a. Diesel trucks and other engines on the roadways are major sources of nitrogen dioxide in the atmosphere so you will see higher levels where these are present.

3. Answer: d. Volatile organic compounds from aerosols and indoor products most contribute to indoor air pollution when the ventilation is poor.