定语从句所有省略问题.关系代词及先行词可省略和不可省略部分分别造句举例说明.看到有人说从句做主语时不能省略,The boy who is standing at the door is my brother.The boy standing at the door is my brother .它又能省略,我很困惑.请高手回答,不确定的请不要回答,
问题描述：
定语从句所有省略问题.关系代词及先行词可省略和不可省略部分分别造句举例说明.
看到有人说从句做主语时不能省略,The boy who is standing at the door is my brother.
The boy standing at the door is my brother .
它又能省略,我很困惑.请高手回答,不确定的请不要回答,
答