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. In creating a lens a lens designer attempts to “trap” light by forcing all the rays arising from a single point in the subject to focus on a single point in the image, as a consequence of their passing through a series of transparent( 透明的) 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 bevirtually, if not actually, infinite. Therefore in lens design, as inchess, perfect solutions to a problem are beyond reach. Although this article will be concerned only with the design of photographic lenses, 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 staggering 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 lens 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 lower, in spite of the fact that 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.
1.Lens design and chess playing are similar in that ____.
A) the final goal and the means by which it can be reached are known
B) perfect solutions to a problem can be found
C) any one decision at any point along the way to the goal can bring numerous possible results
D) both A and C
2.The final goal of designing a lens is ____.
A) to trap the opponent's lenses
B) to focus light with lenses
C) to hand make lenses at low cost
D) to reflect light by means of curved surfaces
3.After the passage the author will talk about ____.
A) the principles of designing lenses
B) techniques of making contact lenses
C) the design of photographic lenses
D) styles of lenses
4.Which of the following words cannot be used to describe today's lenses?
A) More delicate. B) Cheaper. C) Numerous. D) Unpopular.
5.Lens designers today ____.
A) have a large source of help to fall back on B) receive a low salary
C) are less respectable than those of the past D) are not decisive in the lens design
參考答案：
1.答案D。見文章第一段四至六句，相似之處在于最終目標以及達到目標的手段都是 明確的，只是在任一環(huán)節(jié)上所作的任何一項決定都可能導致無數(shù)個結果。
2.答案B。見文章第三句“創(chuàng)造鏡片時，設計者試圖‘捕捉'光線，他們迫使源自物 體某個點的所有光線穿過一組曲度準確的透鏡，結果光線集中在影像的一個點上。”
3.答案C。第一段的最后一句說“ this article will be concerned only with the design of photographic lenses”，故C正確。contact lenses隱形眼鏡
4.答案D。第二段第四句說“另外一些其設計有百年之老的鏡片現(xiàn)在可以大批量生產(chǎn) 且造價低廉。”根據(jù)此句可推出現(xiàn)在的鏡片還保持著傳統(tǒng)，但并不能推出它們是“不受歡迎 的”。故答案是 D。
5.答案A。依據(jù)是第二段的第一句話。 B，C和D文章沒談到。decisive果斷的。
