Mike is a good teacher, which is know to all.
非限制性定语从句常见的用法是：修饰前面整个句子或定语从句前面的一个词。
非限制性定语从句是否可以修饰主句中的任何一个名词呢？很少见这样的例子。
这里的which is know to all是非限制性定语从句，which 指Mike is a good teacher，而不是指 teacher。即：That Mike is a good teacher is know to all.
