7. Our hometown is no longer the one (that) it used to be.= Our hometown is not the same as it used to be.= Our hometown is different from what it used to be.= Our hometown is not what it used to be.
whom: 宾格，在从句中作宾语; 只可指人
1.I like the students who/that work hard. (主语)
2.All who heard the story were amazed. (代词如he, they, any, those, all, one等后多用who.)
3.Chaplin, for whom life had once been very hard, was a success as an actor. (宾语)