参考答案

正确答案：D
解析：题目问：作者是怎样表明梅森英明的领导能力的?文章最后一句“in one brief moment of brilliantleadership．into a statesman whose work would endure to influence the lives and fortunes of those“millions yet unborn”of whom he and his generation of Americans spoke so frequently and thought so constantly．”通过这段话可知，Mason的政治成就影响了美国政治制度的建设，因此也给美国民众带来了莫大幸福。但却是短暂的。据此判断，应选择D。