Mary was grateful when she was told where to set on the bus

当他被告知停在这家戏院的公共汽车的位子时,他很感激。Mary主语 was 系动词 grateful 表语when she was told was told where to set on the bus at the theatre时间状语从句she主语was told 谓语（被动）where to set 宾语（疑问词+不定式） on the bus 宾语的定语at the theatre是bus的定语。