Why was travel by boat between Greenland and Europe made increasingly difficult from about 1350 to 1850?
A) because of increasing cyclonic storms
B) because of increasing sea ice
C) because of widespread piracy
D) because of marine wildlife predator
Answer: B) because of increasing sea ice
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Winds are advecting a new air mass (blue temperature profile) to location A, replacing the old air mass (green temperature profile). Which of the following is true? [INSERT FIGURE 6-11. NO CAPTION]
A) The new air mass is more unstable than the old air mass. B) The old air mass is more unstable than the new air mass. C) The environmental lapse rate of the old air mass is greater than that of the new air mass. D) The new air mass is more stable than the old air mass.
The isohypses portrayed here show
A. low pressure, southern hemisphere. B. high pressure, northern hemisphere. C. low pressure, northern hemisphere. D. high pressure, southern hemisphere.
During the 1950s people lived on average more than two decades longer in developed countries than in developing ones. In the twenty-first century, the gap is ________
A) less than 5 years B) less than 10 years C) less than 15 years D) still the same E) increased to 30 years
A pharmaceutical company wishes to study a possible new headache medicine. They are doing human trials with 1,000 volunteers who experience frequent headaches. The researchers will need to ________
A) control for the type of headache—stress, migraine, or other causes B) have 10 volunteers in the control group C) put all women in the control group and all men in the experimental group D) give all 1,000 volunteers the same amount of the new medication