The Mid-Autumn Festival,which falls on the 15th day of the 8th lunar month,is one of the mostimportant festivals in china.选项有四个是：which,that,when,what答案是which,最关键的是我不知道为什么不选when
问题描述：
The Mid-Autumn Festival,which falls on the 15th day of the 8th lunar month,is one of the most
important festivals in china.
选项有四个是：which,that,when,what
答案是which,最关键的是我不知道为什么不选when
答
The Mid-Autumn Festival,which falls on the 15th day of the 8th lunar month,is one of the most important festivals in China.
如果用 when 表示中秋节可能在任何日子而不是八月十五日. Which 特别指那中秋节节庆.
答
which
本题考查定语从句.由于从句没主语,排除when(when/ where在定语从句里只能作状语,不能作主语,因为它们是副词）选择定语从句的引导词关键看它在从句中作啥成分.