这题最开始的解释当中是这样说的“the participle supplementing would normally be expected to modify the first clause,descibing or extending its meaning,but the logic of this sentence demands a contrast, not a extension”这句的意思不是说supplementing是描述扩展前面主句的,不是用来对比的。而E选项中又说它是用来做对比的……