47. ___
A. Why water flows from artesian springs.
B. How artesian wells are drilled.
C. Why artesian springs are important to geologic research.
D. How aquifers are formed.
48. ___
A. They pump water from the aquifer.
B. They purify the water in the aquifer.
C. They store excess water from the aquifer.
D. They trap water in the aquifer.
49. ___
A. By eroding layers of sediment above it.
By traveling through cracks in layers of rock.
C. By reversing its flow down the aquicludes.
D. By boiling up through pores in the aquifer.
50. ___
A. It pushes the water upward.
B. It keeps the water cool.
C. It holds the water underground.
D. It creates holes in the aquiclude.
40. ___
A. The skills cowboys learned on the range.
B. The evolution of rodeos.
C. The recent decline in the popularity of rodeos.
D. The growth of the cattle industry.
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