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为了提高程序的易读性，同的为减少错误，提高软件开发效率，编码时应注意养成良好的 【2】 。
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阅读下面短文，回答问题。 树是一部活档案，树干的年轮就是历史的记录。1901年，美国人道格拉斯发现居住地附近新近砍伐留下的树桩上，都有相同的图案纹理，譬如说，这些树木年轮的外面三圈都较宽，这表明近3年居住地附近环境与气候条件较好，树木生长较快。相反的结论也可以由此得出。这个发现促使道格拉斯致力于树木年轮的深入研究。他用“同一地区，同时期年轮模式相同”的假设，以“接龙”的方式，来推算老树的初生年份。比如，有一棵被砍伐的百年古树，其砍伐年代不详，但是它的年轮中有一圈与当地一棵1864年砍下的大树的年轮最外圈相吻合。由于最外圈是被砍伐当年的年轮，因此这相吻合的一圈为1864年的年轮。由此向内按每进一圈是一年的方法推算，就可以算出这棵树大约哪一年栽种的。 一些科学家还根据年轮推算出发生过酸雨的年份。哥伦比亚大学的雅格比解释说，随着树木越长越老，年轮也变得越来越窄，而酸雨对树木恰恰起着相反在作用。年轮还可以记录下火山爆发与地震。火山爆发时，大量灰尘与气体进入同温层，遮住了阳光，这会使温度降到冰点以下，给树木留下一道叫做“霜轮”的特殊标记。东印度群岛坦波拉山爆发曾使1816年成了“没有夏天的一年”，这个标记甚至出现在南非的树木上。地震也可以给树木造成损害，使树在以后的一些年中形成较窄的年轮。由此看来，倘若说树木年轮“泄漏天机”，似乎并不为过。 (佚名《年轮》) “相反的作用”是指：
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第二篇 Video recorders and photocopiers, even ticket machines on the railways, often seem unnecessarily difficult to use. Last December I bought myself a video cassette recorder(VCR) described as "simple to use". In the first three weeks I failed repeatedly to program the machine to record from the TV, and after months of practice I still made mistakes. I am not alone. According to a survey last year by Ferguson, the British manufacturer, more than one in four VCR owners never use the timer(定时器) on their machines to record a programme: they don’ t use it because they’ve found it far too hard to operate. So why do manufacturers keep on designing and producing VCRs that are awkward to use if the problems are so obvious. First, the problem we notice are not obvious to technically minded (有技术思想的) designers with years o[ experience and trained to understand how appliances work. Secondly, designers tend to add one or two features at a time to each model, whereas you or I face all a machine’ features at once. Thirdly, although finding problems in a finished product is easy, it is too late by then to do anything about the design. Finally, if manufacturers can get away with selling products that are difficult to use, it is not worth the effort of any one of them to make improvements. Some manufacturers say they concentrate on providing a wide range of features rather than on making the machines easy to use. But that gives rise to the question, "Why can’t you have features that are easy to use" The answer is you can. Good design practice is a mixture of specific procedures and general principles. For a start, designers should build an original model of the machine and try it out on typical members of the public—not on colleagues in the development laboratory. Simple public trials would quickly reveal many design mistakes. In an ideal world, there would be some ways of controlling quality such as that the VCR must be redesigned repeatedly until, say, 90 per cent of users can work 90 per cent of the features correctly 90 per cent of the time. The author had trouble operating his VCR because
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