1. I was the only person in my office who was invited. 我是我们办公室唯一被邀请的人。

试比较：

2. His dog, which was now very old, became ill and died. 他的狗当时很老了, 生病后就死了。

3. Yesterday I met Li Lei, who seemed to be very busy. 昨天我碰上李雷了,他好象很忙。

(如果把从句部分去掉, 整个句子的含义就变了),限定性定语从句

(去掉从句, 主句的意义仍然完整:他的狗生病死了。)非限定性定语从句

(去掉从句, 意义仍然完整:昨天我碰上李雷了。)非限定性定语从句