i don't know choose which one为什么不对?

i don't know choose which one为什么不对? I don't know choose which one.哪里错了?那为什么 I can't choose which i don't know which one/which to choose选哪一个,为什么?再举例几个 I don,t know which one _____ （choose) I really don't know which one to choose i don't know which one to choose I don't konw which one i will choose.I don't know _________o i don't know which one to choose.请造几个类似which ...to 的句子 i don't know which one to choose.中Iwhich one 是KNOW的宾语 ,那么to I don't know which sweater _____(choose) I don't know which watch _____(choose). I don't know which sweater to choose.动名词