COURSE ANSWERS 1.
Answer: d. Both methane and carbon dioxide helped keep the earth warm in its early days, even as the sun was not as bright.
2.
Answer: a. Plants were responsible for the large deposition of waste carbon onto the earth. This carbon later became things like petroleum and other carbon products used today.
3.
Answer: c. The Eocene epoch was a time of increased global temperatures in recent millennia so that trees and animals inconsistent with the northern latitudes today thrived in that environment.
4.
Answer: b. The percent volume of nitrogen in the air is nearly 78 percent.
5.
Answer: a. The percent volume of oxygen in dry air is relatively stable throughout the earth at around 21 percent.
6.
Answer: b. The exosphere is by far the widest layer of our atmosphere, extending from 700 to 10,000 kilometers.
7.
Answer: b. Stratosphere. This is where you will exclusively see the ozone layer.
8.
Answer: d. The stratosphere has polar nacreous clouds in it; these are essentially the only clouds you'll see routinely in this layer.
9.
Answer: b. The heat in the thermosphere is barely felt because the hot gas molecules are so far apart; the air is not very dense at all in this layer.
10.
Answer: b. The ionosphere is made by the ionization of particles from solar radiation. This phenomenon creates the aurorae.
11.
Answer: d. 1° longitude or latitude is about 69 miles anywhere on the earth.
12.
Answer: c. The prime Meridian was arbitrarily selected to be in Greenwich England.
13.
Answer: b. Of these choices, latitude by itself has no impact on the air pressure, while the others do affect it.
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