1．There are various reasons why people write poetry.
人们写诗有各种各样的理由。
reason why...。reason 的意思是“原因，理由”，后面的定语从句常用 why和 that, which 引导，后接同位语从句时要用 that引导，对 reason 的内容进行说明或解释，要注意它们所使用的场合。
①The reason why he failed the English exam was that he didn't learn it well.
