这篇文章提供了20个关系副词的例句，包括“where”，“when”，“why”，“whom”，“whose”，“which”，“that”，“how”，“whoever”，“whatever”，“whichever”，“whenever”，“wherever”，“however”，“as”，“than”，“though”，“while”，“unless”和“as if”，以帮助读者更好地理解和掌握定语从句。

where: The place where we visited last summer was very beautiful.（我们去年夏天参观的地方非常美丽。）

when: The day when we first met was unforgettable.（我们第一次见面的那天是难以忘怀的。）

why: That's the reason why I didn't go to the party.（这就是我没有去参加聚会的原因。）

whom: The girl whom I met at the party was very friendly.（我在聚会上认识的那个女孩很友好。）

whose: The man whose car was stolen reported it to the police.（那辆车被偷的男人向警方报案了。）

which: The book which I borrowed from the library is very interesting.（我从图书馆借的那本书非常有趣。）

that: The hotel that we stayed in was very comfortable.（我们住的那家酒店非常舒适。）

how: I am impressed by how hard she works.（她的努力工作让我印象深刻。）

whoever: Whoever comes to the party should bring a gift.（来参加聚会的人都应该带礼物。）

whatever: The teacher will accept whatever excuse you have for being late.（老师会接受你迟到的任何借口。）

whichever: You can choose whichever color you like.（你可以选择任何你喜欢的颜色。）

whenever: You can call me whenever you need help.（你需要帮助的时候可以随时给我打电话。）

wherever: I will follow you wherever you go.（无论你去哪里，我都会跟着你。）

however: However hard the exam is, I will try my best to pass it.（无论考试有多难，我都会尽力通过它。）

as: The job is not as easy as I thought it would be.（这份工作没有我想象的那么容易。）

than: The shirt is more expensive than I can afford.（这件衬衫比我能承受的价格要贵。）

though: Though he is rich, he is not happy.（虽然他很富有，但他不快乐。）

while: I listened to music while I was doing my homework.（我做作业的时候听音乐。）

unless: Unless you study hard, you will fail the exam.（除非你努力学习，否则你会考试不及格。）

as if: She speaks Chinese as if she were a native speaker.（她讲中文就像是母语人士一样。）