解释介词+which做成分

解释介词+which做成分

...practices in which a person is held responsible for his conduct and given credit for his achievements,
practices是先行词，没错。which指practices，在实践中，用介词in 。还原成：
in the practices a person is held responsible for his conduct and given credit for his achievements,
追问把in the practices放进从句里我是明白的。
但是，为什么可以这样用？从语法来看，定语从句引导词，必须在从句中充当成分，那介词+in which充当什么成分？
介词+which可以在从句中做介宾，或者先行词表时间，地点，原因可用介词+which。但先行词practices在句中应该表实践的含义(那也就没有表示时间，地点或者原因含义)，而且从句也不缺介宾，为什么可以用in which?追答如果将从句分出来，单独说，这句话就应该是这样的，在实践中：in the practices ：
In the practices a person is held responsible for his conduct and given credit for his achievements，
在定语从句中，先行词提前，关系代词就在in的后面。

关系代词whom或which在定语从句中作介词宾语时,介词可放在后面,也可提前构成介词+关系代词whom (先行词指人)/which(先行词指物)引导定语从句(这种方法更为正式).例:
Mary is the girl whom I borrowed a book from.= Mary is the girl from whom I borrowed a book.玛丽就是我向她借书的那个女孩.
Is this the room that/which he once lived in?= Is this the room in which he once lived?这是他曾经住过的房子吗?
常见的有以下几种情况:
1.where=in/on which 例:
This is the room where / in which he lives.这是他住的房间.
I can see the playground where / on which they do sports.我能看见他们进行运动的操场.
2.when= on/in/at which 例:
I still remember the year when/ in which I joined the Party.我仍然记得入党的那一年.
I still remember the day when/on which I joined the Party.我仍然记得入党的那一天.
I still remember the hour when/at which the rocket was launched.我仍然记得那个火箭发射的时刻.
3.why=for which 例:
This is the reason why / for which he was killed.这是他被杀害的原因.
但下列情况下介词不能提前:
⑴用who代替whom,用that代替which时,介词不能提前.例:
He's the boy who I learned English from.这是我向他学英语的男孩.
This should be the place that Tom sent the parcel to.这应是汤姆送包裹的地方.
⑵当whom、which省去时介词不能提前.例:
Is he the boy you went there with?他是和你一起去那儿的男孩吗?
This is the room he lived in.这是他住过的房间.
⑶当whom,which作为含有介词的动词短语的宾语时,介词一般来说不能拆开提前.例:
You're the very man whom I'm looking for.你正是我在找的那个人.
This is the program which he listened to.这就是他听过的节目.
再看下面几种结构:
(一)介词+whose引导的定语从句
whose引导定语从句时,可出现创新句型:介词+whose引导定语从句.解这种定语从句时需弄清从句的动词与先行词、whose后边的名词及定语从句主语之间的关系,并发挥合理想象,不难发现其中正确的逻辑关系.例:
She is the girl to whose father I talked yesterday.她就是昨天我和其父亲谈话的女孩.
He is the boy for whose boss I work.他就是我为其老板打工的男孩.
(二)复杂介词+whom/which引导定语从句
I stay at the hotel at the back of which is a small garden.我住在后面有一座花园的旅馆.
(三)数词(不定量数词)/ 含所属关系名词+of whom/which引导定语从句.例:
She has many books,only one of which is interesting.她有许多书,只有一本是有趣的.

先行词practice是暗含地点的名词,所以in which相当于in the practices做从句中的地点状语追问表实践意思怎么看出暗含了表地点意思名词呢？看不出来啊追答in practices在实践中,这就是表地点