i must have my car repaired 为什么要加 have?

My watch doesn"t work ,I must have it repaired这里的repair为什么用过 I have had the car repaired为什么有had不是have sb done --- Excuse me, I want to have my car repaired, but I can’t f 什么叫逻辑主语 I'll have my car repaired .请问 ,这里的 repaired 的逻辑主语是谁 My watch doesn't work.I must have it _______.A.repaired B.re I have got my watch repaired和got my watch repaired有什么区别 He will have his car repaired next week.repair为什么要用过去时,这句也不是 repair the car have the car repaired 的区别 I should have keep my room clean.为什么加have? You must have your bike ----before I come for it.A.repaired I should have keep my room clean.为什么要加have I should have keep my room clean.为什么要加have啊?