A. can put his design to mass production B. can draw on various sources in his work C. can reduce the cost of lens production D. has no one to train him before taking up the work 参考答案:B 答案解析:第二段第一句指出,与下棋者相比,透镜的设计者有一大优势他可以自由地运用手头上一切可利用的资源(call on any available source of help),帮助他从无数可能性中做出选择。