It is sunday___we often go fishing为什么选in which而不选that

问题描述:

It is sunday___we often go fishing为什么选in which而不选that

It is sunday___we often go fishing
应该是填【on which】
定语从句
先行词【sunday】在从句中作状语【we often go fishing on sunday】
所以不用that
that是做主语宾语的时候用的