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初中三年级英语

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  • 单选题
    Three _____ of the old bridge has fallen down. It's _____.

    A. fifth; safe
    B. fifths; safe
    C. fifth; dangerous
    D. fifths; dangerous
    本题信息:2010年模拟题英语单选题难度一般 来源:张雪
  • 本题答案
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本试题 “Three _____ of the old bridge has fallen down. It's _____.A. fifth; safeB. fifths; safeC. fifth; dangerousD. fifths; dangerous” 主要考查您对

分数

形容词

等考点的理解。关于这些考点您可以点击下面的选项卡查看详细档案。
  • 分数
  • 形容词
分数:
由基数词和序数词构成—分子用基数词,分母用序数词,分子超过“1”时,分母用复数。
例如:a/onesixth(1/6),twothirds(2/3)

英语分数的表示法:
一、用“基数词+序数词”表示
1.分数在英语中通常是借助于基数词和序数词来共同表达的。其中基数词表示分子,序数词表示分母。
如:
The centimeter is one-tenth of the decimeter or one-hundredth of the meter.厘米是分米的十分之一,或者说是米的百分之一。
However,the number of boys will bea third or less than the girls in the class.但是,班里男生的人数将比女生少三分之一或更少。
从以上例子可以看出:
①分子除用one外,也可用a;
②如果分子大于1,分母要用复数形式。但是,1/2不能说a(one)second,而要说a(one)half。例如:
The sum of one half,one third and one fourth of a certain number is 13.某数的1/2,1/3和1/4的和是13。
1/4 和3/4可以说a(one)fourth和three fourths,但常用a quarter和three quarters表示。
③应该注意的是,分数修饰名词时,若该名词是不可数名词只能用单数;
④若是可数名词,用单数或复数均可。但是,若它们在句子中作主语,则谓语动词是用单数还是复数取决于名词,即与分数所修饰的名词保持一致。例如:
Only one-fifth of air consists of oxygen.氧气只占空气的1/5。
About two thirds of the students attendthe meeting.大约2/3的学生都参加了会议。
2.带分数也是常见的英语数词表达。所谓带分数,实际上是“整数+分数”,表达时分而述之,只是整数部分与分数部分要用连词and连接。
当带分数修饰名词时,该名词通常是复数,但若名词置于整数one或a之后,则用单数。
“带分数+名词”作主语时,谓语动词根据临近原则要用复数。例如:
You should finish the work within one and a fourth hours.你应在1.25小时内完成工作。
The atom breaks up in a minute and a quarter.原子在1.25分钟内裂变。

二、用percent等表示
表示百分之一可以说one(a)hundredth,但更常用one percent或percent,即用百分数表示法来表达。例如:
Our bodies are 65percent water.我们人体含65%水分。
Seventy-five percent of the earth'ssur- face is covered by water.地球表面的75%被水覆盖着。
Eighty-five percent of the students in English department are girls.英语系85%的学生是女生。

三、用part表示
名词part有“……分之一”的意思,分子大于1时,part用复数。表示分数的结构一般有以下三种:
1.“基数词(或a)+序数词+part(s)” a hundred part百分之一
2.“基数词+part(s)+in+基数词” five parts in one thousand千分之五
3.“基数词+part(s)+per+基数词” one part per million百万分之一

四、用“基数词+介词+基数词”表示
借助介词表示分数,介词前的数词是分子,介词后的数词是分母。例如:
1.Ninety- nine people out of a hundred,if they were asked who first found America,would answer Clumbus.
如果要问是谁首先发现美洲,一百个人中有九十九个(百分之九十九)将回答是哥伦布。
这种结构中的介词主要有in,out of,of 以及to
2.The map is drawn to a scale of one of ten thousand.
这张地图是按万分之一的比例绘制的。


英语分数表示法:
一般情况下,表示分数时,分子要用基数词,分母用序数词(first, second, third ...)。
如果分子大于1,分母必须用复数形式。
1. "1/2"或"一半"的表示方法:
用one half或a half表示。例如:
半英里:one (a) half mile或half one (a) mile
一个半小时:an hour and a half或one and a half hours (hour要用复数形式)

2. "1/4"的表示方法:
用one (a) quarter表示。如果分子大于1, quarter用复数形式。例如:
1/4  one (a) quarter
3/4three quarters

3. 如果分子大于1,分母要用序数词的复数形式。
如果分数大于1,要用整数部分+ and + 分数表示。例如:
1/3  one third或a third
5/6 five sixths
8 3/5 eight and three fifths

4. 比较复杂的分数用over表示。
分子(基数词)+ over + 分母(基数词)。注意这里分子、分母全用基数词表示。例如:
51/80 fifty-one over eighty
77/232 seventy-seven over two hundred and thirty-two

5. 用"分子(基数词)+ (out) of + every + 分母(基数词)"表示。这里分子、分母也全用基数词表示。例如:
1/7one of every seven
5/9five out of every nine
eg: An investigation showes that about two of every three students in this university are from China.
一项调查表明这所大学大约有三分之二的学生来自中国。

6. 用"分子(基数词)+ in + 分母(基数词)"表示。这里分子、分母也全用基数词表示。例如:
1/3 one in three
5/6 five in six
eg: Only about one in five books was written for children ranged from seven to ten years old.
只有大约五分之一的书是为七到十岁的儿童写的。

7. 用"表示减少意义的动词或词组+ 倍数"表示减少了n-1/n。例如:
eg: The time for the whole journey is shortened 3 times.
整个行程的时间缩短了三分之二(或缩短到原来的三分之一)。

8. 当分数后面接名词时,如果分数表示的值大于1,名词用复数;如果小于1,名词用单数。
3 3/5 kilograms 三又五分之三千克(读作three and three fifths kilograms)
4/5 meter 五分之四米(读作four fifths meter)
5/6 inch 六分之五英寸(读作five sixths inch)
百分数表示法:
百分号%读作percent (per cent),无复数形式,数词要用基数词,应用时常与by连用。例如:

数字

表示法

6%

six percent

0.58%

(naught) point five eight percent

200%

two hundred percent

The output of petroleum went up by twenty percent.石油产量增长了20%。
The price of food was reduced by ten percent. 食品的价格下降了10%。
The loss of electricity has been reduced to less than thirty percent.电的损耗减少到30%以下。 
注意:
由"分数(或百分数)+ of + 名词"构成的名词词组作主语时,其后的动词形式依of词组中的名词类别而定。例如:
Two thirds of the swampland has been reclaimed for farming. 三分之二的沼泽地已经开垦为农田了。
Over sixty percent of the doctors were women. 超过百分之六十的医生是女性。
形容词
简称adj.或a,形容词用来修饰名词或代词,表示人或事物的性质、状态,和特征的程度好坏与否,形容词在句中作定语,表语,宾语补足语。
她是一个好学生,她学习努力。She is a good student, and she works hard.
这辆自行车很贵。This bike is expensive.
对不起,我现在很忙。I am sorry, I'm busy now.
你为这次会议做好准备了吗? Have you got everything ready for the meeting?
形容词的语法功能:
一、作定语
He is the greatest writer alive.他是依然健在的伟大的作家。
Somewone else has done it.别人已经做了这事。
二、作补语
形容词做主语补足语和宾语补足语时,可以表示其现状、状态,也可以表示某一动作的结果,并常用在表示“认为,看待”的动词如believe,prove,consider等候。例如:
The news made her sad.这消息使他感到非常悲伤。
Don't marry young.不要早婚。
三、作状语
形容词或形容词短语可作状语,形容词作状语时,可以看作是“being+形容词”结构的省略,可表示时间、原因、条件、方式、强调或伴随状况等意义。例如:
Enthusiastic,they are co-operative.热心的时候他们是很合作的。
Rich or poor, young or old, we all have problems.不管是穷人还是富人,不管是年轻人还是老人,我们都有问题。
四、做表语
The ship was adrift on unknown seas.那艘船在陌生的海域漂流。
五、做主语
Old and young joined the discussion.
Rich or poor meant the same to him.作感叹语
Very good!Say it again.
Stupid!He must be crasy.

形容词的几个特殊用法:
most 同形容词连用而不用 the, 表示 " 极,很,非常, 十分"。
It's most dangerous to be here. 在这儿太危险。
I cannot do it, it's most difficult. 我干不了这件事,太难了。

"The+形容词比较级..., the+形容词比较级..." 表示 " 越... 就越..."。
The more you study, the more you know. 你学的越多, 就知道的越多。
The more I have, the more I want. 我越有就越想要有。
The more, the better. 越多越好。

" 形容词比较级 + and + 形容词比较级 ", 表示 " 越来越... "。
It's getting hotter and hotter. 天气越来越热了.
It's pity he is getting poorer and poorer. 真可怜他越来越穷了。
The computer is cheaper and cheaper. 计算机越来越便宜。
The more and more people focus on the meeting next year. 越来越多的人关注明年的会议。

主语+谓语(系动词)+as+形容词原形+as+从句。表示两者对比相同。
This box is as big as mine. 这个盒子和我的一样大。
This coat is as cheap as that one. 这件衣服同那件衣服一样便宜。
 I study English as hard as my brother. 我同我兄弟一样学习努力。

the + 形容词 表示某种人。
He always helps the poor. 他经常帮助穷人。
I like to have a talk with the young. 我喜欢同年轻人谈话。
The rich sometimes complain their empty life. 富人有时抱怨他们空虚的生活。
The police led the old man across the street. 警察领老人横过马路。

以-ly结尾的形容词
1) 大部分形容词加-ly可构成副词。但 friendly,deadly,lovely,lonely,likely,lively,brotherly,仍为形容词。
改错:(错) She sang lovely.             (错) He spoke to me very friendly.
   (对) Her singing was lovely.  (对) He spoke to me in a very friendly way.
2)有些以-ly 结尾的词既为形容词,也为副词。
daily,weekly,monthly,yearly,early
The Times is a daily paper.
The Times is published daily.

too+adj.+to句型   “太…而不能”
  He is too young to go to school.
 =He isn’t old enough to go to school.
 =He is so young that he can’t go to school.


形容词的位置:
1.形容词一般放在名词前作定语  
单个形容词修饰名词时,一般要放在名词的前面。它们的前面常常带有冠词、形容词性物主代词、指示代词、数词等。例如:  
a red flower一朵红花
an interesting story一个有趣的故事  
six blind men 六个盲人
my own house我自己的房子
如果有两个或两个以上的形容词修饰一个名词时,则由它们和被修饰的名词之间的密切程度而定,越密切的形容词越靠近名词。
如果几个形容词的密切程度差不多则按音节少的形容词放在前面,音节多的形容词放在后面。  
2.当形容词所修饰的词是由some,any,every,no等构成的不定代词时,形容词必须置于名词之后。例如:  
    She has something new to tell me.她有一些新的情况告诉我。  
    I have nothing important to do today.今天我没有重要的工作要做。  
    Do you know anybody else here?这儿你还有认识的人吗?  
3.形容词后面有介词短语或不定式短语时,形容词必须置于名词之后。例如:  
    It is a problem difficult to work out.这是一道难以解决的问题。  
    Edison is a student difficult to teach.爱迪生是个很难教的学生。  
    This is a kind of flowers easy to grow.这是一种易栽的花。  
4.用 and 或 or 连接起来的两个形容词作定语时一般把它们放在被修饰的名词后面。起进一步解释的作用。例如:  
    All people,young or old,should be strict with themselves.  
    所有的人,无论老少,都应该严格要求自己。  
    We are building a new school, modern and super.  
    我们正在建一所现代化的高档次的新型学校。  
    All countries, rich and poor, should help one another. 所有的国家,无论穷富都应该互相帮助。  
5.有少数形容词,如enough和possible,既可置于所修饰的名词前面也可以置于它所修饰的名词之后。例如:   
Do you have enough time(time enough)to prepare?你有足够的时间做准备吗?   
Maybe it will be a possible chance(chance possible)for you.或许它将成为一次可能的机遇。
6.有些形容词,置于名词之前与之后,含义不尽相同。例如:  
the writer present 出席的作者  
the present writer 现在的作者
7.表示长,宽,高,深,及年龄的形容词,应放在相应的名词之后。
This river is about 100 metres wide.
The building is more than 50 metres tall.
 He is less than 40 years old.
8. enough修饰名词时,在名词前后都可以。
They said that they had enough food.= They said that they had food enough.
 enough 修饰形容词和副词,位于其后。
 He is old enough to join the army.
 He isn’t old enough to go to school.
9.形容词else通常放在疑问代词,疑问副词或不定代词后
 what/who/where/when/when else
 something/anything/nothing…else
 What else did you do?
 Do you have anything else to say?
10.由两个或两个以上的词组成的形容词词组修饰名词时须放在名词之后。
This is the book easy to read.
这是一本容易读的书。


形容词知识拓展:
名词化的形容词:
有些形容词可以和定冠词连用,表示一类人或事物,这时,它相当于一个名词,可作主语或宾语;
表示一类人时,看作复数,表示一类事物时,通常看作单数。
Robin Hooh(罗宾汉) hated the rich and loved the poor.
The old are taken good  care of in American.
the+形容词,常见的短语有:
the old/the young/the sick/the white/
the black/the rich/the poor/the dead(死者)

形似副词的形容词:
以-ly结尾的词通常是副词,但是下列词为形容词。
friendly  lonely (孤独的) ;lively (活着的);lovely(可爱的)

复合形容词的类型:
(1)名词+过去分词  man-made satellite 人造卫星
(2)形容词+现在分词  a good-looking man
(3)形容词+名词  second-hand cars
(4)数词+名词-ed   three-legged chairs三条腿的椅子
(5)数词+名词  400- metre race
(6)副词+现在分词  hard-working students
(7)副词+过去分词  well-known writers
(8)形容词+形容词  a dark-red jacket
(9)形容词+过去分词  ready-made clothes 成品服装

含有形容词的常用句型:
(1) It’s+adj. of sb. to do sth.
(good/ kind/nice/polite/clever/foolish… )
It’s very kind of you to help me.
(2) It’s +adj. for sb. to do sth.
(difficult/easy/hard/dangerous/usefulinteresting/important…)
It’s important for us to learn English well.
(3)下列形容词后常跟动词不定式
 表示情感或情绪的形容词:glad,pleased,sorry,sad,afraid,thankful…
 I'm glad to see you.
表示能力,意志或推测的形容词:ready,able,sure,certain…
 I’m sorry to hear that.

某些现在分词和过去分词可作形容词
the moving story 令人感动的故事
a moved boy   一个被感动的男孩
a frightened child 一个被吓到的孩子
a frightening film 一个恐怖电影