只用that，只用which，只用who引导定语从句情况
1.先行词是不定代词,如all, few, little, much, none,something, everything , anything, nothing等;2.先行词被不定代词修饰,如all, any, every, few,much, little, no, some等;3.先行词被序数词或形容词最高级修饰;4.先行词被the only, the very, the same, the last, the right等修饰;5.先行词现有些人又有物。
只用that引导定语从句情况
６.被修饰词为数词时。    Yesterday I caught two fish and put them in a basin of water. Now you can see the two
that are still alive.７.当主句是以 which，who, what开头特殊疑问句时。８.主句是There be结构，修饰其主语定
语从句宜用that作关系代词。There's still a seat in th ...