Which of the following most logically completes the
argument?
A photograph of the night sky was taken with the
camera shutter open for an extended period. The
normal motion of stars across the sky caused the
images of the stars in the photograph to appear as
streaks. However, one bright spot was not streaked.
Even if the spot were caused, as astronomers believe,
by a celestial object, that object could still have been
moving across the sky during the time the shutter was
open, since\underline{AB}.
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Athe spot was not the brightest object in the
photograph
分析该选项
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Bthe photograph contains many streaks that
astronomers can identify as caused by
noncelestial objects
分析该选项
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Cstars in the night sky do not appear to shift
position relative to each other
分析该选项
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Dthe spot could have been caused by an object
that emitted a flash that lasted for only a fraction
of the time that the camera shutter was open
分析该选项
-
Eif the camera shutter had not been open for
an extended period, it would have recorded
substantially fewer celestial objects
分析该选项
显示答案
正确答案: D