题目

A new technique ______ , the yields as a whole increased by 20 percent. A. working outB. having worked outC. having been worked outD. to have been worked out

A new technique ______ , the yields as a whole increased by 20 percent.
  • A. working out
  • B. having worked out
  • C. having been worked out
  • D. to have been worked out

题目解答

答案

C

解析

步骤 1：分析句子结构
句子的主干是 "the yields as a whole increased by 20 percent"，表示“整体产量增加了20%”。前面的部分需要一个非谓语动词短语来修饰整个句子，表示“一种新技术被开发出来”。
步骤 2：确定非谓语动词的形式
由于“一种新技术被开发出来”这个动作发生在“整体产量增加了20%”之前，所以需要使用完成时态。同时，由于“一种新技术”是“被开发出来”的，所以需要使用被动语态。
步骤 3：选择正确的选项
根据以上分析，选项C "having been worked out" 符合要求，表示“一种新技术已经被开发出来”。