定语从句的省略情况,请看下面两个句子This is my brother ( who is) going to Australia.The man ( who is ) standing behing the counter.为什么第一句中who is 不能省略,第二句中who is 可以省略
问题描述：
定语从句的省略情况,请看下面两个句子
This is my brother ( who is) going to Australia.
The man ( who is ) standing behing the counter.
为什么第一句中who is 不能省略,第二句中who is 可以省略
答