定语从句
书上写：
as引导非限定性定语从句时，先行词可以是一个词，也可以是一个短语或句子。
能否各举一个例子，即先行词是一个词时，先行词是一个短语时，先行词是一个句子时。
参考答案:As we know, smoking is harmful to one's health
China has basically succeeded in defeating SARS, as we have expected
单词
The conference, as we had expected, was put off