你将先行词带进后面的从句中,第一句就是i studies in the school three years ago.这里in the school做地点状语,所以用where.你也可以理解为in+that=where
同理第二句就是i visited the school yesterday.是宾语,所以是宾语从句.
第二题也一样,放入从句中发现提到前面来的是on the days.所以on+that=when.
一个是spent time in beijing.作宾语.
引导词其实很简单,比如in the way 就变成the way where.不需要合并介词的话就是普通的that/which.其中that不能用在非限定性定语从句
for which =why 所以for the reason=the reason why