Earth experiences ice ages partly because there are variations in Earth's
A) greenhouse gas levels.
B) sea level.
C) seismic activity.
D) tilt and orbit.
D
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One advantage of wind power is that it
A. is limited to land areas B. is not noisy. C. does not interfere with wildlife or habitats. D. produces little to no direct carbon dioxide emissions. E. does not require a lot of space.
Soil, once it is contaminated with hydrocarbons, cannot be cleansed. Indicate whether the statement is true or false
Your friend shows you a purple-colored mineral sample he recently found while walking the beach. He claims that it must be quartz, because the color matches that of another quartz sample he saw in a museum. Do you think his identification is accurate?
A. Yes; the mineral quartz is almost always the color purple. B. Maybe; further tests must be done to positively identify the mineral, since quartz can come in many different colors. C. No; the mineral quartz is never purple.
Surface pressure systems tend to move in the same direction as the wind at 5500 m (18,000 ft)—the 500-mb level. The speed at which surface systems move is about double the speed of the winds at this level
a. True b. False