定语从句
( attributive clause)
学 时 数, 2
作 者:宗麟
教学内容
? 定语从句的基本用法
? 关系代词与关系副词
? 限制性定语从句与非限制性定语从句
? 关系代词” That”与” Which”
? As在定语从句中的用法
定语从句的基本用法
用来修饰主句中某一名词或代词,或修饰整个
句子或主句中一部分,而起定语作用的句子叫
作定语从句 (Attributive subordinate clause),又
称关系从句 (Relative Clause)。 受定语从句修
饰的词叫先行词 。 定语从句一般由关系代词或
关系副词引导,通常跟在先行词后面做后置修
饰语,
?Eg,
The boy who is standing at the door is my son,站
在门边的那个男孩是我的儿子,(“The boy”为定
语从句, who is standing at the door”的先行词 )
Eg,Yesterday,I happened to meet the professor
whom I got know at a party, 昨天我碰巧遇见
了那位我在一次聚会上认识的教授。 (,whom
I got know at a party,为, the professor”的定语
从句,”the professor”为先行词,)
先行词与关系词
1.先行词与关系词的有内在联系, 先行词与关
系词之间实质上是互等、互换的关系。也就
是说,关系词的作用就是将先行词所表达意
义, 代到, 从句中来起作用,
Eg,Some people who are successful language
learners often fail in other fields such as
physics and mathematics.有些在语言学习上
很有成就的人,在其他领域诸如物理,数学之
类却一窍不通。
先行词与关系词
2,先行词的意义决定关系词的选择, 关系词的
选择往往是由先行词自身表达的意义,以
及它在从句中的语法功能而决定的,
如,先行词自身表达的意义是表示, 人的意义,
或是, 物的意义,,那么我们就相应地选
择表示, 人的意义, 或是, 物的意义, 的
先行词。,
Eg,Apes have been able to communicate in
sounds which have a specific meaning and
yet are no words,猿已经能用声音交流了,
这些声音有意义但不是词。
有时先行词本身是表示事物的名词,而它在
从句中却与介词构成了短语,在从句中充
当状语,在这种情况下,我们就应该用关
系副词而不能用关系代词了。
Eg,The waitress lead police to the hotel room
where the murder happened,女服务员把警察
领到了发生谋杀案的那个旅馆房间,
关系代词 用来指代先行词是人或物的名词或
代词
句子
成分
用于限制从句或非限制性从句 只用于限制性从句
代替人 代替物 代替人或物
主语 Who Which That
宾语 Whom Which That
定语 Whose
Of whom
Whose
Of which
Eg,Have you heard of the album the pop
singer who came from a seaside town,你听过
那位来自一个海滨小城的歌星的专辑吗?
Eg,This is the room that Lu xue was
born in,这就是鲁迅出生的那个房间。
Eg; The book which I am reading is
revised from the movie,The Day
After Tomorrow”.我正在读的书是改
编自电影, 后天,
Eg,The desk whose leg is broken is
handed down by my grandfather.那张
断腿的书桌是我祖父传下来的。
关系副词 在定语从句中代替相应的先行词,
并且在从句中分别起时间,地点和原因的状语
结构
关系副词 被替代的先行词 在从句中的作用
When
at/on/in/during which
表示时间的名词 时间状语
Where
in/at which
表示地点,场合等的名词 地点状语
Why
for which
只有 reason 原因状语
Eg; People will always remember the time
when( on which) the south and the
north reunited 。人们会永远记住南方和
北方重新团结起来的那一时刻。
Eg,That is a beautiful campus where( on
which) I made a lot dreams 那是一座我
曾经在那儿有过许多梦想的美丽的校园
Eg,The manager explained the reason to us
why (for which) he had misunderstood us
before 。 经理向我们解释为什么他以前会误
解我们的原因。
关系副词
1.why 不能引导非限制性定语从句
2,关系代词 that 有一种特殊的用法。 That 在
限制性定语从句中可以作状语,表示时间、
地点、原因和方式,代替 when,where,why,
或, 介词 +which”,
Eg,We will never forget the year
that (when) SARS broke out in China.
我们决不会忘记非典在中国肆虐的这
一年,
Eg,The newest discovery shows us the
reason that (why) the ancient city has been
kept perfect for more than 2000 years.最新
的发现向我们展示了那座古城为什么能
完好的保存了两千年,
Eg,I don?t like
the way that (in which) they show up.
我不喜欢他们出现的方式
关系副词
3,from where中的 where 为关系代词
Eg,He took the attic as his bedroom,from
where he could see the whole city.他把顶
层阁楼作为他的卧室,从那里他可以看见
整座城市
1.that 指物,有时也可以指
人,which 指物,不能人。
Which(包括 who,whom) 和
that 通常能够互换,
关系代词 That与 Which
Eg,Views that (which ) are entirely new
or foreign may be extremely hard to
accept for those aged people,那些全新
的或是来自国外的观点对于上了年纪
的人来说可能特别难以接受,
Eg,Those points which (that) the
academician stressed in his report are
very important indeed.院士在报告里
强调的几点的确很重要,
关系代词 That与 Which
2.如果关系代词在定语从句中作宾语可
以省略。
Eg,This is the book (which/that) you
were looking for yesterday, 这就是你
昨天找的那本书。
Eg,The letter (that/which) I received
yesterday came from one of my
former classmates.我昨天收到的信
是我以前的一个同学寄来的
关系代词 That与 Which
3.There be 句型做定语从句时,做主语的关系代词
也常省去,
Eg,Here comes the first bus there is across the
boundary.马上到来的是第一辆穿越国境线的公
交车
关系代词 That
1.先行词本身是 all,everything,
something,nothing,anything等不
定代词时,关系代词只能用, that”,
Eg,They had nothing that could cure of his
sadness of having lost his wife,他们任何
能治愈他丧妻之痛的东西了。
Eg,Anything that can burn is a source of
heat energy,任何能够燃烧的东西都是
热能。
Eg,There must have been something that
happened to him when he walked out
alone,在他独自出门的时候一定出了什
么事。
关系代词 That
2,先行词已有序数词或形容词的最高级或
the last,the only等作定语时,关系代词
只能用, that”,
Eg,This is the most impressive comic
movie that has never been put on show
before, 这是以前从未上演过的最有感
染力的喜剧片。
Eg,We have to consider the first thing that
starts the new school year, 我们必须要考
虑开始新学年的第一件事。
Eg,That is the only way that leads to your
success,那是通向你成功的唯一之路。
关系代词 That
3,先行词是人和物时,要用 that 而不用
which/who引导定语从句,
Eg,He talked about those writers and their
books that were completely unknown to us.他
讲的都是我们根本不知道的作家和他们的
书,
Eg,We were deeply impressed by the teachers
and schools that we had visited in the
mountainous regain.我们在山区访问过的老
师和学校给我们留下了深刻的印象,
关系代词 which
1.,介词+关系代词, 关系代词只可用
whom或 which,不可用 that,介词可
以是 in,on,about,from,for,with,to
at,of,without 等,可以引导限制性
定语从句,也可以引导非限制性定语
从句,
?Eg,The world in which we live is
made of matter, 我们生活于其中的世
界是由物质组成的。
Eg,The conference invited the scholar to whom
the article referred.这次会议邀请了文章中提
到的那位学者,
? Eg,There are only about twenty thousand
people taking part in the election,one
seventh of whom are hardly educated,大约
有两万人参加了选举,其中七分之一的人
几乎没有受过任何教育
关系代词 which
2,which可作表语,既可指人,以可指
物。指人时,一般指从事某种职业
或是有种特征.品性或才能的人
关系代词 which
3.如果作先作词的集体名词着眼于集体
的整体,关系代词用 which;若是指集
体中的各个成员,则用 who。
Eg,The people,which is the basis of a
country,should be stressed in any
constitution,作为国家的基础,人民在
任何一部宪法中都应得到重视
Eg,People who came from the same
region tend to talk in dialect to each
other.来自同一地区的人喜欢用他们
的方言交谈,
但 如果先行词是 anyone,anybody,
everyone,everybody,someone,somebody,
关系代词应该用 who 或 whom,不用
which。
Eg,Is there anyone here who will go with
you?有没有人要跟你一起去,
关系代词 which
4.先行词本身是 that 时,一般用 which
引导定语从句。
Eg,The curse of the Pharaoh
is that which was caved on the wall
of their pyramid.法老的诅咒就是写
在他们的金字塔的墙上的 (那些文
字 )
关系代词 which
5,非限制性定语从句中,关系代词只能用
which,而不能用 that,作宾语用的关系代词
也不能省略。
Eg,She is fond of speaking French,which
indeed she spoke very well,
她喜欢说法语,她的确讲的很好,
Eg,We lodged with an old lady of the
village,whom we all liked,我们寄
宿在村里的一位老太太家里,我们
都喜欢她,
关系代词 which
6,which还可以引导非限制性定语从句,修饰前
面的整个主句,代替主句所表示的整体概念
或部分概念。
Eg,He succeeded in the competition,
which paved him an easy road to
university.他在竞赛中获胜,这为他
进大学铺平了道路,
Eg,He was waked in the midnight by a
call of stranger,which annoyed him
very much,他在午夜时分被一个陌生
人的电话吵醒,这让他非常恼火,
限制性定语从句
限定性定语从句与主句的关系很紧奏,对先行词起限定、
修饰的作用。如果将其去掉,会影响句子意思的完整
性;有时甚至于引起费解、误解。
Eg,They explained the reason to me why
they had forgot their promise,他们向
我解释为什么他们会忘了他们的承诺。
Eg,Those who want to go hiking please
sign their name here.想要去徒旅行的
人在这里签名,
Eg,We don?t know the exact time
when the next negotiation will be
held, 我们不知道下一轮谈判举行
的确切时间。
非限制性定语从句
关系代词和关系副词都可以引导非限
制性定语从句,
Eg,His speech,which bored everyone,
went on and on.他还在继续那令人
乏味的演讲,
Eg,My friend arrived at 8:30,when I
was on the bus to my office.我的朋
友是 8:30到的,当时我正在去公司
的公交车上
Eg,She had went to the sunny beach,
where the witch said she is most likely
to meet her Mr,Right,她去了阳光灿
烂的海滩,据巫婆说,她最有可能 在
那里遇见她的终身伴侣,
非限制性定语从句
非限定性定语从句在形式上就与主句很松散,
它与主句之间有一个逗点,,, 隔开;它对其
先行词或全句起补充、说明的作用,而没有限定、
修饰的作用。即使将其去掉,也不会影响句子
意思。
Eg,The sun heats the earth,which
makes it possible for fauna and flora
to grow,(句中的非限定性定语从句
是对全句进行补充、说明,将全句表
达的意思看成, 一件事情)。太阳
给予大地热,这就使动植物的生长
成为可能。
Eg,The combination of satellites,which transmit
information,computers,which store
information,and television,which displays
information,will change every home into an
education and entertainment center,(三个从句
分别对起先行词起补充说明的作用 )卫星能传
输信息,计算机能储存信息,电视能显示信
息,把这些手段结合起来可以使每个家庭都
成为教育娱乐的中心。
限制性定语从句与非限制性定语从句的区
别
在中文译文里,我们往往将非限制性定语从
句作为一个分句处理,而不把它作定语翻
译,
Eg,The old lady has an vase,which is
made from crystal.(此句中,非限定
性定语从句是对先行词 vase进行补充、
说明 )
这位老太太只有一只花瓶,是水晶质地
的,
?如果将此句改写成限定性定语从句,
The old lady has a vase which is made from
crystal.(此句中,限定性定语从句就要对先行
词 vase进行限定、修饰 )
这位老太太有一只水晶花瓶 (可能还有其他不
是水晶制的花瓶 )
as在定语从句中的用法
1.as多与 such 或 the same连用引导限度
性定语从句,可以代替先行词是人或物的名词。
Eg,This is the same brand of watch as I
have lost.这块表和我丢了的那块是一
个牌子,
Eg,I had never heard of such story as
he told.我还没有听过象他讲的那
样的故事,
as在定语从句中的用法
2.as 也可单独使用,引导非限制性定语从句,
作用相当于 which。位置较灵活,可以位于
主句前面.中间或后面,一般用逗号与主句
隔开,但 which所引导的非限制性定语从句
只能放在主句之后,
Eg,The elephant?s nose is like a snake,as
anybody can see.大象的鼻子像蛇一样,
这是任何人都看的到的,
Eg,As is expected,the Gold Digger won the
final match.如大家所愿,掘金者队赢得了决
赛胜利,
Eg,The engineer,as may be expected,was
very strict with figures.工程师对数字很
严格,这是可以估计到的,
( attributive clause)
学 时 数, 2
作 者:宗麟
教学内容
? 定语从句的基本用法
? 关系代词与关系副词
? 限制性定语从句与非限制性定语从句
? 关系代词” That”与” Which”
? As在定语从句中的用法
定语从句的基本用法
用来修饰主句中某一名词或代词,或修饰整个
句子或主句中一部分,而起定语作用的句子叫
作定语从句 (Attributive subordinate clause),又
称关系从句 (Relative Clause)。 受定语从句修
饰的词叫先行词 。 定语从句一般由关系代词或
关系副词引导,通常跟在先行词后面做后置修
饰语,
?Eg,
The boy who is standing at the door is my son,站
在门边的那个男孩是我的儿子,(“The boy”为定
语从句, who is standing at the door”的先行词 )
Eg,Yesterday,I happened to meet the professor
whom I got know at a party, 昨天我碰巧遇见
了那位我在一次聚会上认识的教授。 (,whom
I got know at a party,为, the professor”的定语
从句,”the professor”为先行词,)
先行词与关系词
1.先行词与关系词的有内在联系, 先行词与关
系词之间实质上是互等、互换的关系。也就
是说,关系词的作用就是将先行词所表达意
义, 代到, 从句中来起作用,
Eg,Some people who are successful language
learners often fail in other fields such as
physics and mathematics.有些在语言学习上
很有成就的人,在其他领域诸如物理,数学之
类却一窍不通。
先行词与关系词
2,先行词的意义决定关系词的选择, 关系词的
选择往往是由先行词自身表达的意义,以
及它在从句中的语法功能而决定的,
如,先行词自身表达的意义是表示, 人的意义,
或是, 物的意义,,那么我们就相应地选
择表示, 人的意义, 或是, 物的意义, 的
先行词。,
Eg,Apes have been able to communicate in
sounds which have a specific meaning and
yet are no words,猿已经能用声音交流了,
这些声音有意义但不是词。
有时先行词本身是表示事物的名词,而它在
从句中却与介词构成了短语,在从句中充
当状语,在这种情况下,我们就应该用关
系副词而不能用关系代词了。
Eg,The waitress lead police to the hotel room
where the murder happened,女服务员把警察
领到了发生谋杀案的那个旅馆房间,
关系代词 用来指代先行词是人或物的名词或
代词
句子
成分
用于限制从句或非限制性从句 只用于限制性从句
代替人 代替物 代替人或物
主语 Who Which That
宾语 Whom Which That
定语 Whose
Of whom
Whose
Of which
Eg,Have you heard of the album the pop
singer who came from a seaside town,你听过
那位来自一个海滨小城的歌星的专辑吗?
Eg,This is the room that Lu xue was
born in,这就是鲁迅出生的那个房间。
Eg; The book which I am reading is
revised from the movie,The Day
After Tomorrow”.我正在读的书是改
编自电影, 后天,
Eg,The desk whose leg is broken is
handed down by my grandfather.那张
断腿的书桌是我祖父传下来的。
关系副词 在定语从句中代替相应的先行词,
并且在从句中分别起时间,地点和原因的状语
结构
关系副词 被替代的先行词 在从句中的作用
When
at/on/in/during which
表示时间的名词 时间状语
Where
in/at which
表示地点,场合等的名词 地点状语
Why
for which
只有 reason 原因状语
Eg; People will always remember the time
when( on which) the south and the
north reunited 。人们会永远记住南方和
北方重新团结起来的那一时刻。
Eg,That is a beautiful campus where( on
which) I made a lot dreams 那是一座我
曾经在那儿有过许多梦想的美丽的校园
Eg,The manager explained the reason to us
why (for which) he had misunderstood us
before 。 经理向我们解释为什么他以前会误
解我们的原因。
关系副词
1.why 不能引导非限制性定语从句
2,关系代词 that 有一种特殊的用法。 That 在
限制性定语从句中可以作状语,表示时间、
地点、原因和方式,代替 when,where,why,
或, 介词 +which”,
Eg,We will never forget the year
that (when) SARS broke out in China.
我们决不会忘记非典在中国肆虐的这
一年,
Eg,The newest discovery shows us the
reason that (why) the ancient city has been
kept perfect for more than 2000 years.最新
的发现向我们展示了那座古城为什么能
完好的保存了两千年,
Eg,I don?t like
the way that (in which) they show up.
我不喜欢他们出现的方式
关系副词
3,from where中的 where 为关系代词
Eg,He took the attic as his bedroom,from
where he could see the whole city.他把顶
层阁楼作为他的卧室,从那里他可以看见
整座城市
1.that 指物,有时也可以指
人,which 指物,不能人。
Which(包括 who,whom) 和
that 通常能够互换,
关系代词 That与 Which
Eg,Views that (which ) are entirely new
or foreign may be extremely hard to
accept for those aged people,那些全新
的或是来自国外的观点对于上了年纪
的人来说可能特别难以接受,
Eg,Those points which (that) the
academician stressed in his report are
very important indeed.院士在报告里
强调的几点的确很重要,
关系代词 That与 Which
2.如果关系代词在定语从句中作宾语可
以省略。
Eg,This is the book (which/that) you
were looking for yesterday, 这就是你
昨天找的那本书。
Eg,The letter (that/which) I received
yesterday came from one of my
former classmates.我昨天收到的信
是我以前的一个同学寄来的
关系代词 That与 Which
3.There be 句型做定语从句时,做主语的关系代词
也常省去,
Eg,Here comes the first bus there is across the
boundary.马上到来的是第一辆穿越国境线的公
交车
关系代词 That
1.先行词本身是 all,everything,
something,nothing,anything等不
定代词时,关系代词只能用, that”,
Eg,They had nothing that could cure of his
sadness of having lost his wife,他们任何
能治愈他丧妻之痛的东西了。
Eg,Anything that can burn is a source of
heat energy,任何能够燃烧的东西都是
热能。
Eg,There must have been something that
happened to him when he walked out
alone,在他独自出门的时候一定出了什
么事。
关系代词 That
2,先行词已有序数词或形容词的最高级或
the last,the only等作定语时,关系代词
只能用, that”,
Eg,This is the most impressive comic
movie that has never been put on show
before, 这是以前从未上演过的最有感
染力的喜剧片。
Eg,We have to consider the first thing that
starts the new school year, 我们必须要考
虑开始新学年的第一件事。
Eg,That is the only way that leads to your
success,那是通向你成功的唯一之路。
关系代词 That
3,先行词是人和物时,要用 that 而不用
which/who引导定语从句,
Eg,He talked about those writers and their
books that were completely unknown to us.他
讲的都是我们根本不知道的作家和他们的
书,
Eg,We were deeply impressed by the teachers
and schools that we had visited in the
mountainous regain.我们在山区访问过的老
师和学校给我们留下了深刻的印象,
关系代词 which
1.,介词+关系代词, 关系代词只可用
whom或 which,不可用 that,介词可
以是 in,on,about,from,for,with,to
at,of,without 等,可以引导限制性
定语从句,也可以引导非限制性定语
从句,
?Eg,The world in which we live is
made of matter, 我们生活于其中的世
界是由物质组成的。
Eg,The conference invited the scholar to whom
the article referred.这次会议邀请了文章中提
到的那位学者,
? Eg,There are only about twenty thousand
people taking part in the election,one
seventh of whom are hardly educated,大约
有两万人参加了选举,其中七分之一的人
几乎没有受过任何教育
关系代词 which
2,which可作表语,既可指人,以可指
物。指人时,一般指从事某种职业
或是有种特征.品性或才能的人
关系代词 which
3.如果作先作词的集体名词着眼于集体
的整体,关系代词用 which;若是指集
体中的各个成员,则用 who。
Eg,The people,which is the basis of a
country,should be stressed in any
constitution,作为国家的基础,人民在
任何一部宪法中都应得到重视
Eg,People who came from the same
region tend to talk in dialect to each
other.来自同一地区的人喜欢用他们
的方言交谈,
但 如果先行词是 anyone,anybody,
everyone,everybody,someone,somebody,
关系代词应该用 who 或 whom,不用
which。
Eg,Is there anyone here who will go with
you?有没有人要跟你一起去,
关系代词 which
4.先行词本身是 that 时,一般用 which
引导定语从句。
Eg,The curse of the Pharaoh
is that which was caved on the wall
of their pyramid.法老的诅咒就是写
在他们的金字塔的墙上的 (那些文
字 )
关系代词 which
5,非限制性定语从句中,关系代词只能用
which,而不能用 that,作宾语用的关系代词
也不能省略。
Eg,She is fond of speaking French,which
indeed she spoke very well,
她喜欢说法语,她的确讲的很好,
Eg,We lodged with an old lady of the
village,whom we all liked,我们寄
宿在村里的一位老太太家里,我们
都喜欢她,
关系代词 which
6,which还可以引导非限制性定语从句,修饰前
面的整个主句,代替主句所表示的整体概念
或部分概念。
Eg,He succeeded in the competition,
which paved him an easy road to
university.他在竞赛中获胜,这为他
进大学铺平了道路,
Eg,He was waked in the midnight by a
call of stranger,which annoyed him
very much,他在午夜时分被一个陌生
人的电话吵醒,这让他非常恼火,
限制性定语从句
限定性定语从句与主句的关系很紧奏,对先行词起限定、
修饰的作用。如果将其去掉,会影响句子意思的完整
性;有时甚至于引起费解、误解。
Eg,They explained the reason to me why
they had forgot their promise,他们向
我解释为什么他们会忘了他们的承诺。
Eg,Those who want to go hiking please
sign their name here.想要去徒旅行的
人在这里签名,
Eg,We don?t know the exact time
when the next negotiation will be
held, 我们不知道下一轮谈判举行
的确切时间。
非限制性定语从句
关系代词和关系副词都可以引导非限
制性定语从句,
Eg,His speech,which bored everyone,
went on and on.他还在继续那令人
乏味的演讲,
Eg,My friend arrived at 8:30,when I
was on the bus to my office.我的朋
友是 8:30到的,当时我正在去公司
的公交车上
Eg,She had went to the sunny beach,
where the witch said she is most likely
to meet her Mr,Right,她去了阳光灿
烂的海滩,据巫婆说,她最有可能 在
那里遇见她的终身伴侣,
非限制性定语从句
非限定性定语从句在形式上就与主句很松散,
它与主句之间有一个逗点,,, 隔开;它对其
先行词或全句起补充、说明的作用,而没有限定、
修饰的作用。即使将其去掉,也不会影响句子
意思。
Eg,The sun heats the earth,which
makes it possible for fauna and flora
to grow,(句中的非限定性定语从句
是对全句进行补充、说明,将全句表
达的意思看成, 一件事情)。太阳
给予大地热,这就使动植物的生长
成为可能。
Eg,The combination of satellites,which transmit
information,computers,which store
information,and television,which displays
information,will change every home into an
education and entertainment center,(三个从句
分别对起先行词起补充说明的作用 )卫星能传
输信息,计算机能储存信息,电视能显示信
息,把这些手段结合起来可以使每个家庭都
成为教育娱乐的中心。
限制性定语从句与非限制性定语从句的区
别
在中文译文里,我们往往将非限制性定语从
句作为一个分句处理,而不把它作定语翻
译,
Eg,The old lady has an vase,which is
made from crystal.(此句中,非限定
性定语从句是对先行词 vase进行补充、
说明 )
这位老太太只有一只花瓶,是水晶质地
的,
?如果将此句改写成限定性定语从句,
The old lady has a vase which is made from
crystal.(此句中,限定性定语从句就要对先行
词 vase进行限定、修饰 )
这位老太太有一只水晶花瓶 (可能还有其他不
是水晶制的花瓶 )
as在定语从句中的用法
1.as多与 such 或 the same连用引导限度
性定语从句,可以代替先行词是人或物的名词。
Eg,This is the same brand of watch as I
have lost.这块表和我丢了的那块是一
个牌子,
Eg,I had never heard of such story as
he told.我还没有听过象他讲的那
样的故事,
as在定语从句中的用法
2.as 也可单独使用,引导非限制性定语从句,
作用相当于 which。位置较灵活,可以位于
主句前面.中间或后面,一般用逗号与主句
隔开,但 which所引导的非限制性定语从句
只能放在主句之后,
Eg,The elephant?s nose is like a snake,as
anybody can see.大象的鼻子像蛇一样,
这是任何人都看的到的,
Eg,As is expected,the Gold Digger won the
final match.如大家所愿,掘金者队赢得了决
赛胜利,
Eg,The engineer,as may be expected,was
very strict with figures.工程师对数字很
严格,这是可以估计到的,