,The school committee finally caved in to the demands of parents and teachers.请教孙老师在这句语里""to""是作什么用处?""demand""在这里是作名词用,我就想不明白""to""的用处了?谢谢!

to 是介词，表示对于，介词+名词，很正常的用法。

可是不是已经有了介词""IN""吗?""TO""是否能省略?谢谢!

caved in 是个词组。

谢谢!