语法与词汇 ---- as taste is really a composite sense made up of both taste and smell.

A、 To which we refer
B、 What do we refer to
C、 That we refer to it
D、 What we refer to

【正确答案】 D

【答案解析】答案：D 分析：句子谓语动词是 is，此题考点为主语从句。AB可以排除，C中，that不做任何成分，没有意义，但是it作为主语从句中的宾语，没有明确指代是什么。D，what做从句中refer to 的宾语，符合主语从句的语法规则。翻译：我们所提到的味觉实际上是一种由味觉和嗅觉混合在一起的感觉。