I can't decide---- A.to buy which one B.which one to buy C.t

根据decide可以排除AC,不能用to根据语序,D也错选B 再问： 那decide to do sth是什么时候用？ 再答： VERB决定，拿定主意（做）If you decide to do something, you choose to do it, usually after you have thought carefully about the other possibilities。 这里是宾语从句，不一样的，decide to do 这个搭配有的,这里出现了特殊句式，搭配就不存在了