1 He lives far from the city. 介词短语from the city修饰副词far，构成副词短语，副词短语far from the city作动词的地点状语。

2 He is good at football. 介词短语at football修饰形容词good，构成形容词短语，形容词good at football作表语。

3 In London, many people have dinner in Chinese restaurants. 介词短语in London修饰全句，而不是修饰谓语动词。