1. As it happens, I went to university there!

2. She told me the whole story exactly as it happended.

句1，As it happens 是传统语法的非限制性定语从句；现代语法的比较状语从句。

现在，As it happens 一般看作是一个习语，意为 “碰巧”。一般现在时表示以现在说话时间为准，主句可以是过去时。此句可以转化为：It happens that I went to university there. （碰巧，我在那里上的大学。）

句2，as it happended 是真正的方式状语从句，修饰主句谓语动词 told。

She told me the whole story exactly as it happended. 她把整个故事原封不动地告诉了我。

上次那个句子：Life as we know it needs water and oxygen.曹老师分析得很好。as we know it 是描述主语的。