E The boy who is standing at the door is my son. yH 在门边的那个男孩是我的儿子(“ The boy为定 语从句” who is standing at the door”的先行词)❖ Eg: The boy who is standing at the door is my son. 站 在门边的那个男孩是我的儿子.(“The boy”为定 语从句”who is standing at the door”的先行词）