If CFCs have not been widely used since the late 20th century, why are they considered a major greenhouse gas in the 21st century?
A) Although they have been banned, they are being use illegally
B) CFCs are released by a number of natural processes, such as volcanoes
C) Greenhouse gases such as methane will break down into CFCs
D) CFCs can stay in the atmosphere for decades
Answer: D
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At any given time, how many jet streams can most often be found in the atmosphere of the northern hemisphere?
A. 1 B. 2 C. 10 D. 20
Examine the figure that shows the sequence of strata in three Colorado Plateau national parks. Which unit(s) are shared by Grand Canyon National Park and Zion National Park?
A) Toroweap and Kaibab B) Kaibab and Monekopi C) Moenkopi and Chinle D) Kaibab only
The ________ and the Alpine Fault of New Zealand are examples of transform plate boundaries.
A. Choctaw Fault of Oklahoma B. East African Rift C. New Madrid Fault of Arkansas D. San Andreas Fault of California E. Rio Grande Rift
What role does weathering play in mass wasting?
A. It is caused by physical weathering. B. It is caused by chemical weathering. C. None of these choices are correct. D. All of these choices are correct.