Multiple Choice
Identify the
letter of the choice that best completes the statement or answers the question.
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1.
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Balance in the water cycle means that ____. a. | the average annual precipitation over Earth equals the amount of water
that evaporates | b. | water that falls
to Earth only enters oceans | c. | the amount of water that falls to Earth weighs the same as the
amount that condenses in clouds | d. | water that
evaporates from Earth’s surface remains forever in the atmosphere | | |
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2.
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The ability of a stream to erode and transport material depends
largely on its ____. a. | width | c. | velocity | b. | length | d. | density | | | | |
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3.
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The
single most important erosional agent on Earth is ____. a. | wind | c. | ocean
waves | b. | glaciers | d. | running water | | | | |
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4.
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If
you were to examine the profile of a typical stream, you would probably find that the gradient
is ____. a. | steepest near
the mouth | b. | steepest near the head | c. | about the same
at both the head and the mouth | d. | gentler near the head | | |
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5.
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The
vertical drop of a stream channel over a certain distance is called ____. a. | discharge | c. | gradient | b. | channel roughness | d. | runoff | | | | |
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6.
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A stream’s discharge ____. a. | decreases between its source and
mouth | b. | remains the same throughout its
course | c. | is greatest during times of drought | d. | increases
between its source and mouth | | |
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7.
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In a
typical stream, where the gradient is steep, the discharge ____. a. | is
small | c. | cannot be
determined | b. | is large | d. | is very large | | | | |
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8.
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If a
river originates 200 meters above sea level and travels 400 kilometers to the ocean, what is the
average gradient in meters per kilometer? a. | 0.5 m/km | c. | 5 m/km | b. | 2
m/km | d. | 0.2
m/km | | | | |
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9.
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As
stream discharge increases, which of the following occurs? a. | Stream velocity,
channel width, and depth all increase. | b. | Stream velocity, channel width, and depth all
decrease. | c. | Stream velocity increases, but channel width and depth both
decrease. | d. | Stream velocity decreases, but channel width and depth both
increase. | | |
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10.
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Base level is ____. a. | any part of the
stream that is below sea level | b. | the lowest point to which a stream can erode its
channel | c. | the source from which the stream
flows | d. | the elevation of a stream’s largest
tributary | | |
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11.
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What
is the ultimate base level of a stream? a. | a large lake | c. | a resistant layer of rock | b. | the
ocean | d. | a larger
stream | | | | |
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12.
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Lowering a stream’s base level will cause the stream to ____. a. | deposit
sediment | c. | change
course | b. | meander | d. | downcut | | | | |
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13.
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One major cause of floods is ____. a. | rapid spring snow melt | c. | light rain over a large area | b. | a decrease in
stream discharge | d. | increased
capacity of stream channels | | | | |
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14.
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One
traditional flood control method has been to attempt to keep the stream’s flow within its
channel by creating ____. a. | meanders | c. | artificial levees | b. | artificial
cutoffs | d. | flood control
dams | | | | |
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15.
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Groundwater is found underground in the zone of
____. a. | aeration | c. | saturation | b. | soil | d. | sediment | | | | |
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