很高兴为你回答
选call at,表拜访,我去到他家,结果发现他出去了
Call at (1).访问（某处）；（2）.（车船等）停靠（某地）.
We called at Mr.Smith yesterday.昨天我们拜访了史密斯先生家.
The train calls at every station.火车每站必停
Call on (1).访问（sb.）,(2).号召；要求
I called on the director at his office.我到主任的办公室找他.
Call for (1).需要,要求（有……）.（2）.去取（sth.）,去接（某人同往某处）
He’ll call for the mail on his way home.在回家的路上他要去取邮件.
I’ll call for you at 6 o’clock and we’ll go to the theatre together.
The occasion calls for quick action.情况需要采取紧急行动.
call out大声叫；调来；请去：They boy called out for help．那个男孩大声呼救.We hope it will not be necessary to call out the army．我们希望不必要出动军队
