one 用作替代词主要用于替代“a＋单数可数名词”，表泛指；若需特指，则用 the one。如：A fast train is one that goes fast. 快车是一种行驶快的火车。The accident was similar to one that happened in 2008. 这个事故与发生在2008年的事故类似。Open the drawer on the left, the one with a key in it. 打开左边的抽屉，上面有钥匙的那个。Here are six rings. Pick out the one you like best. 这里有六枚戒指，选出你最喜欢的一枚。I want very much to see these films, especially the one you mentioned. 我很想看这些电影，特别是你提到的那一部。注：the one与that均可表特指，但前者只用于替代单数可数名词，而后者则可用于替代可数或不可数名词。
和平海棠
