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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.
What explanation is given for the use of the subtractive method in modern color films?
选项 A、Subtractive colors are more realistic.
B、The subtractive process is more efficient.
C、Additive chemical techniques are too complex.
D、The additive process is still being developed.
答案B
解析 细节推断题。根据关键词modern color films(现代彩色胶卷)为原文尾段尾句的重现，对答案进行定位。在关键词的前面提到，the subtractive method…has turned out to be more practical，其中practical与选项B中的efficient对应。故答案为B。选项A“减色法颜色更加现实”文中没有提及，故将之排除。根据原文尾段尾句可知选项C的句子的主语应该是the subtractive method(减色法)而不是Additive chemical techniques(加色化学技术)；选项D，原文没有提及。
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