单项选择题

Cells in the parvo system can distinguish between two colors at any relative brightness of the two. Cells in the color-blind magno system, on the other hand, are analogous to a black-and-white photograph in the way they function: they signal information about the brightness of surfaces but not about their colors. For any pair of colors there is a particular brightness ratio at which two colors, for example red and green, will appear as the same shade of gray in a black-and-white photograph, hence any border between them will vanish. Similarly at some relative red-to-green brightness level, the red and green will appear identical to the magno system. The red and green are then called equiluminant. A border between two equiluminant colors has color contrast but no luminance contrast. The author uses all of the following in the discussion in the third paragraph EXCEPT:

A. an example.
B. definition of terms.
C. contrast.
D. a rhetorical question.
E. analogy.
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Hank Morgan, the hero of Mark Twain’s A Connecticut Yankee in King Arthur’s Court, is a nineteenth-century master mechanic who mysteriously awakening in sixth-century Britain, launches what he hopes will be a peaceful revolution to transform Arthurian Britain into an industrialized modem democracy. The novel, written as a spoof of Thomas Malory’s Morted’ Arthur, a popular collection of fifteenth-century legends about sixth-century Britain, has been made into three upbeat movies and two musical comedies. None of these translations to screen and stage, however, dramatize the anarchy at the conclusion of A Connecticut Yankee, which ends with the violent overthrow of Morgan’s three-year-old progressive order and his return to the nineteenth century, where he apparently commits suicide after being labeled a lunatic for his incoherent babblings about drawbridges and battlements. The American public, although enjoying Twain’s humor, evidently rejected his cynicism about technological advancement and change through peaceful revolution as antithetical to the United States doctrine of progress. The author uses the examples of three upbeat movies and two musical comedies primarily in order to demonstrate that
A. well-written novels like A Connecticut Yankee in King Arthur’s Court, regardless of their tone or theme, can be translated to the stage and screen.
B. the American public has traditionally been more interested in watching plays and movies than in reading novels like A Connecticut Yankee in King Arthur’s Court.
C. Twain’s overall message in A Connecticut Yankee in King Arthur’s Court is one that had a profound impact on the American public.
D. Twain’s A Connecticut Yankee in King Arthur’s Court has been a more popular version of the Arthurian legends than has Malory’s Morted’ Arthur.
E. A Connecticut Yankee in King Arthur’s Court has been accepted as an enjoyable and humorous tale in versions that have omitted the anarchy at the novel’s conclusion.
单项选择题
Cells in the parvo system can distinguish between two colors at any relative brightness of the two. Cells in the color-blind magno system, on the other hand, are analogous to a black-and-white photograph in the way they function: they signal. information about the brightness of surfaces but not about their colors. For any pair of colors there is a particular brightness ratio at which two colors, for example red and green, will appear as the same shade of gray in a black-and-white photograph, hence any border between them will vanish. Similarly at some relative red-to-green brightness level, the red and green will appear identical to the magno system. The red and green are then called equiluminant. A border between two equiluminant colors has color contrast but no luminance contrast The author mentions a black-and-white photograph most probably in order to explain
A. how the parvo system distinguishes between different shapes and colors.
B. how the magno system uses luminosity to identify borders between objects.
C. the mechanism that makes the magno system color-blind.
D. why the magno system is capable of perceiving moving images.
E. the brightness ratio at which colors become indistinguishable to the parvo system.
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