get it repaired ,为什么用repaired?

I'will get it repaired .这里为什么要加ed? get it repaired对吗?还是用make 或是have? get your watch repaired It is being repaired. is it the watch you want to have repaired 中have repaired 为什么 My watch doesn"t work ,I must have it repaired这里的repair为什么用过 it was repaired this morning When can you get my car repaired?I need it tomorrow.It (.)be get it repaired是一种什么结构,get可以换成什么词,repaired是过去分词吗,在这里作定语还是补语? My computer has broken down I will get it repaired this afte I’ll have to get the bicycle repaired.为什么repair放在 is it the watch you want to have repaired为什么不是to repair