【英语达人进来帮忙（关于定语从句）,这里有三对句子：1、TheschoolwhereIstudyisverybeautiful.Theschoolwhich/thatIvisitedyesterdayisbeautiful.2、ThedaywhenIwasbornisJune6th.Thedaywhichspentwithherisunc】

　　英语达人进来帮忙（关于定语从句）,

　　这里有三对句子：

　　1、TheschoolwhereIstudyisverybeautiful.

　　Theschoolwhich/thatIvisitedyesterdayisbeautiful.

　　2、ThedaywhenIwasbornisJune6th.

　　Thedaywhichspentwithherisuncomfortable.

　　3、ThereasonwhyIwaslateisjustanexcuse.

　　Thereasonwhich/thatIgaveisjustanexcuse.

　　这三对句子的引导词为什么不一样啊?什么情况下用关系代词,什么情况下用关系副词啊?感觉分辨不清楚.能帮我详细分析一下这三对句子的句子成分吗?越详细越好（本人英语不好）.