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Designing a lens can be compared to playing chess. In chess a player tries to trap his opponent’ s king in’ a series of moves. O
Designing a lens can be compared to playing chess. In chess a player tries to trap his opponent’ s king in’ a series of moves. O
admin
2009-02-10
26
问题
Designing a lens can be compared to playing chess. In chess a player tries to trap his opponent’ s king in’ a series of moves. On creating a lens, lens designers attempts to "trap" light by forcing all the rays arising from a single point in the subject to converge on a single point in the image, as a consequence of their passing through a series of transparent elements with precisely curved surfaces. Since in both cases the ultimate goal and the means by which it can be attained are known, one is tempted to think there will be a single best decision at any point along the way. The number of possible consequences flowing from any one decision is so large, however, as to be virtually, if not actually, infinite. Therefore in lens design, as in chess, perfect solutions to a problem are beyond reach. The same principles apply to all lenses.
The lens designer has one enormous advantage over the chess player. The designer is free to call on any available source of help to guide him through the countless number of possibilities. Most of that help once came from mathematics and physics, but recently computer technology, information theory, chemistry, industrial engineering and psychophysics have all contributed to making the designer’ s job immeasurably more productive. Some of the lenses on the market today were inconceivable a decade ago. Others whose design is as much as a century old can now be mass-produced at low cost. With the development of automatic production methods, lenses are made by the millions, both out of glass and out of plastics. Today’ s lenses are better than the best lenses used by the great photographers of the past. Moreover, their price may be lower, in spite of the fact that the 19th century craftsmen worked for only a few dollars a week and today’ s lenses are more complex. The lens designer cannot fail to be grateful for the science and technology that have made his work easier and his creations more widely available, but he is also humbled: it is no longer practical for a fine photographic lens to be designed from beginning to end by a single human mind.
In lens design,______.
选项
A、it is completely impossible to preset the best steps along the way
B、it is always very hard to solve any problems
C、one can work out a best solution to problems in each step
D、there are countless steps towards the final goal
答案
A
解析
第一段最后三句指出,然而,每走一步所可能产生的后果如果不能说是无穷无尽的(infinite),至少也可以说是多不胜数。因此,正像下棋一样,设计透镜不可能有解决问题的完美方法,设计各类透镜都是如此(The same principles apply to all lenses)。意为:根本不可能在制作过程中预设出最佳步骤。
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0
专业英语四级
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