【题目】At the awarding ceremony held in Tokyo, the scientists were surprised by what ______ in science and technology.
A. has discovered B. has been discovered
C. had discovered D. had been discovered
在线课程【答案】D
【解析】句意：在东京举行的颁奖仪式上，科学家们惊讶于科学技术的发现。科学家们感到惊讶是过去式，故科学技术发现用过去完成时，what于动词discover是被动关系，故选D。