Question

He __________ his aunt’s when he went to Wuhan on business.

A．called on

B．called at

C．dropped in on

D．dropped in

Answer 1

B

词义用法辨析。call on 号召，call at 拜访  drop in on sb拜访drop in 拜访（不及物） 句意为“当他去武汉出差时他顺便拜访了姑姑家。”  his aunt’s为处所而C项要搭配人作宾语所以答案为B。