1.当先行词是【物】时,我们可以用【关系代词which,that引导定语从句修饰】先行词【物】；which和that在定语从句中【做主语或宾语】2.当先行词是【人】时,我们可以用【关系代词who,whom,that引导定语从句修饰】先行词...