参考答案

正确答案：A
解析：文章中第一段，“Computers have been taught to play not only checkers，but also championship chess，which is a fairly accurate yardstick for measuring the computer's progress in the ability to learn from experience”表明计算机不仅能够跟一般棋手下棋，而且能够跟世界冠军下棋这是计算机取得进步的里程碑，因为计算机可以具有通过经验学习的能力了。其中yardstick 表示里程碑，和选择项A中的develop in to a new stage相符，因此选A。对于选择项B，文章第二段第三句“In theory this is a sensible approach；in practice it is impossible”说明计算机要每局必赢在理论上是可行的，但是在实践上是不可行的。因此，B要排除。文章第三段的第一句“Therefore，if the computer is to compete at championship levels，it must be programmed to function with less than complete data”表明如果计算机要与世界冠军相抗衡，它的程序中的资料也是不全的。这就说明答案C是不符合题意的。文章最后一段第一句“There are other proofs that computers can be programmed to learn”论证了选择项D的错误，因为D computers can be programmed to play and reason but not learn 认为计算机只能用于玩耍和推理，而没有学习的能力，这与原文是相左的。所以答案选Aplaying championship chess shows computer's program has been developed into a new stage．