定语从句有三个问题,我是菜鸟,越详细越好,可追加财富,

定语从句有三个问题,我是菜鸟,越详细越好,可追加财富,
1.I ate the apple 和my mum gave me the apple 组合成的定语从句为什么会是i ate the apple which my mum gave me .合成的句子之前的中心词是the apple ,它的定语从句可以是the apple which i ate my mum gave me 或者是the apple which my mum gave me i ate 为什么
2.he married a gril +the girl is beautiful 的定语从句是不是the gril who he married is beautiful（这个好像是错的,我只是感觉,是不是因为who 相当于从句的主语了,又来个he ,相当于有有两个主语了?）
3.he who married the girl won the lottery＝ he who won the lottery married the gril 只是定语不一样
4.当先行词在主句中是宾语/表语时,定语从句是不是直接加在先行词后面?eg:he married the girl who is beautiful ...i ate the apple +the apple is green 为什么会是the apple which i ate is green ,那为什么会出现 问题3的句型或者说i ate the apple +the apple is green = i ate the apple which is green