请问为什么要加's'to get one's money's worth

请问为什么要加's'to get one's money's worth get to one's To get one's to get better grades,grade为什么要加s get to one's feet to get one's back to waste time is to idle away one's life ,请问,这里的是“to”什么作用,为什么要加to. 请问he is one of my father's friends为什么要加ONE she must go to the baker`s to get some cakes.其中get前面为什么要加to do sth to the best of ones ability为什么要加to? he wants to get good grades in math.为什么grades要加s how does he gets to school get为什么要加 s to get one's hair 如题 He is always the last one [to get ]to school为什么要用to get to get to work为什么开头要加to she helps her sister to get dressed every day 中为什么get不加s It is easy for him to get tired中的get为什么不加s? She helps her sister get dressed every dag 为什么get不加s?声明：get前没to