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  3. There are two ways to create colors in a photograph. One method, called additive, starts with three basic colors and adds them t

There are two ways to create colors in a photograph. One method, called additive, starts with three basic colors and adds them t

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问题     There are two ways to create colors in a photograph. One method, called additive, starts with three basic colors and adds them together to produce some other color. The second method, called subtractive, starts with white light(a mixture of all colors in the spectrum)and, by taking away some or all other colors, leaves the one desired.
    In the additive method, separate colored lights combine to produce various other colors. The three additive primary colors are green, red and blue(each providing about one third of the wavelengths in the total spectrum). Mixed in varying proportions, they can produce all colors. Green and red light mix to produce yellow; red and blue light mix to produce magenta; green and blue mix to produce cyan. When equal parts of all three of these primary-colored beams of light overlap, the mixture appears white to the eye.
    In the subtractive process colors are produced when dye(as in paint or color photographic materials)absorbs some wavelengths and so passes on only part of the spectrum. The subtractive primaries are cyan(a bluish green), magenta(a purplish pink)and yellow; these additive primaries or dyes that absorb red, green and blue wavelengths respectively, thus subtracting them from white light. These dye colors are the complementary colors to the three additive primaries of red, green, and blue. Properly combined, the subtractive primaries can absorb all colors of light, producing black. But, mixed in varying proportions, they too can produce any color in the spectrum.
    Whether a particular color is obtained by adding colored lights together or by subtracting some light from the total spectrum. The result looks the same to the eye. The additive process was employed for early color photography. But the subtractive method, while requiring complex chemical techniques, has turned out to be more practical and is the basis of all modern color films.
Which of the following is NOT a pair of additive and subtractive primary colors?
选项 A、Yellow and blue.
B、Magenta and green.
C、Black and white.
D、Cyan and red.
答案C
解析 细节判断题。根据题干的关键词additive and subtractive primary colors(加色法和减色法的三原色)分别定位到原文第二段和第三段。原文第二段第二句提到加色法的三原色为green，red和blue，原文第三段第二句提到减色法的三原色为cyan(a bluish green)，magenta(a purplish pink)和yellow，没有黑色与白色。故答案为C。
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