英语选择加讲解

来源：百度知道 编辑：UC知道 时间：2024/05/22 15:12:32
68. A new technique ______ , the yields as a whole increased by 20 per cent.

A)working out
B) having worked out
C)having been worked out
D)to have been worked out

C 解析：a new technique having been worked out为独立主格结构作状语。
having been worked out与后面主句的主语the yields之间没有主动或被动关系，因此分词加了分词自己的主语，因此称为独立主格。

祝进步。

C