题目内容：

这个定语从句的先行词是哪个?
the great wall is the longest wall that has ever existed in the world.中的先行词是哪个?
到底是wall 还是great wall
不是说关系代词紧跟先行词后吧?

优质解答

先行词是the great wall,has ever existed in the world是定从.由于前面有 is the longest wall 最高级修饰,所以关系代词用that.