1) 关系代词: 指人 who(主宾),whom(宾),that
指物 which(主宾),that
2) 关系副词作状语：when,where(前两个都可用介+which替代); why(可用for which替代)
3) whose作定语“...的”: 指人/物 A的B, 也可替换成of which(物)/of whom(人)
解题技巧：
(1)从句不完整缺成分,用关代: +不及物动词+
介词+
(2)从句完整,先行词具有表时间、地点、原因(reason/excuse)特征，用关系副词
(3)主从句完整且先行词和主语存在A和B关系，用whose
The man who lives in that house is my uncle.(缺主语)
That is the girl (who/whom,that) I met at the party yesterday.(缺宾语met sb.)
The audience which is compesed of students is largest than ever.
(which除了指物外，还可指人的属性，如身份、职业、地位等)
She remembered the day when/on which he had first walked into her office.(on the day)
We then moved to Paris,where/in which we lived for 6 years. (in Paris)
You're the only one (whose/of whom) advice he may listen to.(你的建议)
You live in a room (whose/of which) window opens to the south.(房子的窗户)
只用that情况：
(1)当先行词是all,everything,nothing,something,anything,little,none,few等不定代词时
(2)当先行词是序数词或形容词最高级时
(3)当先行词被no,every,any, only,very,much等限定词修饰时
(4)当先行词有人又有物时
(5)当先行词为主句的表语或关系代词为从句的表语时
(6)there be句型中，且先行词为物时
(7)当先行词前有who,which,what等特殊代词时
All that we need is the support from you.
The first lesson that I learned will never be forgotten.
He is the only person that I want to see.
The passengers and parcels that filled the car were mixed.
Our school is no longer the school that it used to be.
(it used to be sth. that作表语)
There is a room in the building that is still free.
Who is the lady that is waiting at the school gate.
