【题目】The inner thought of the two young persons are revealed in the book, _________ both of them fail to express.
A. where B. when C. what D. which
在线课程【答案】D
【解析】
考查非限定性定语从句。句意：这两个年轻人的想法在书中得到了提示，但他们都没有表达出来。此处为非限定性定语从句，先行词为The inner thought，指物，关系词在从句中作express的宾语，故D项正确。