Question

【题目】( 2016·浙江)11. Scientists have advanced many theories about why human beings cry tears , none of ______ has been proved.

A. whom B. which C. what D. that

Answer 1

【答案】B

【解析】

试题分析：句意：关于人类为什么哭的时候会流泪，科学家已经提出了很多理论，没有一个被证明了。使用定语从句，先行词是theories，指物，定语从句中用代词+介词+关系代词which引导。故选B。