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.