到底是call sb on+电话号码还是call sb at+电话号码

call on1.PHRASAL VERBIf you call on someone to do something or call upon them to do it,you say publicly that you want them to do it.呼吁; 公开请求例：One of Kenya's leading churchmen has called on the government to resign.肯尼亚宗教界的一位重要人物已呼吁政府下台.2.PHRASAL VERBIf you call on someone or call upon someone,you pay them a short visit.短暂访问例：Sofia was intending to call on Miss Kitts.索菲娅打算去拜访基茨小姐.
call sb at给某人打电话
call out at对某人高声叫喊
call at1.到…作短暂访问,访问(某地)：They called at Mr Brown's office last Thursday.上星期四他们曾到布朗先生的办公室去拜访他.2.(车、船等)在…停靠(或停留)：This ship doesn't call at Hongkong.这只船在香港不停靠.