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1、四. 数 词 数词是表示数目多少或先后顺序的词,有基数词和序数词两种。表数量的数词叫基数词，如one, two, three。表顺序的数词叫序数词，如first, second, third, fourth, fifth,.一构成1112单独记 one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve2)1319词尾为-teen：thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen3)2090逢整十词尾为-ty：twenty
2、, thirty,forty,fifity,.4)21 99在十位数和个位数之间加连字符构成，如： 73 seventy-three, 88 eighty-eight5)101 999先说几百，再加and,再加末尾两位数，如： 178 one hundred and seventy-eight6)1000以上的数词，先从后向前数，每三位用一个数逗点“，隔开。第一个“，是thousand千，第二个“，是million百万，第三个“，是billion美语中的十亿英国用thousand million，然后一节一节地用几百几十几的方法来数。注意英语中没有“万，用ten thousand 10,000
3、表示十万的表示法：one hundred thousand 100,000百万的表示方法：a/one million 1,000,000千万及以上的表示法： 2百亿 twenty thousand million英，twenty billion美 万亿，兆a trillion=a million million =1012,(旧指-尤英国，百万兆，1018)二基数词的使用 基数词可在句中作主语、表语、定语、状语、介宾、同位语。TwoTwo and two are four. 表语We twoTwo thousand三基数词使用的考前须知1hundred, thousand, million,
4、billion, score(20),dozen(12)前有数词表示具体数目时，这些词不加复数。当前无数词时，这些数词要加复数后再加of 连接名词，来表示不具体量。如：five hundred people, two score apples, hundreds of people, scores of pears, thousands of, thousands and thousands of, tens of thousands of, millions of, a few hundred men, many thousands of men, some/several million(
5、s of) men2)表示“几十”的数词的复数形式前用形容词性物主代词修饰可用来表示“在某人十几岁时；用定冠词修饰表示“年代。in ones early twenties(thirties)在某人二十三十几岁时the 1840s/the 1840s 19世纪40年代the 1980s/the 1980s 20世纪80年代十亿以上的大数，英美有不同的表示： 英国英语 美国英语十亿thousand million one billion百亿ten thousand million ten billion千亿hundred thousand million one hundred billion万亿
6、one thousand billion one trillion 年代的读法: 297读作two ninety-seven或two hundred and ninety-seven 1908读作nineteen and eight或nineteen o eight或nineteen hundred and eight 1949读作nineteen forty-nine或nineteen hundred and forty-nine 读作two thousand4)a.在美国英语中，表示几点过几分可用after,表示几点差几分可用before。如:12点10分：ten after twelve
7、。11点50分：ten before twelve。b.假设想说明是上午，可在时间后加上am或a. m.(a.m.是拉丁语ante meridiem的缩写，意为“上午)，假设想说明是下午，可在时间后加上pm或p. m. (p.m.是拉丁语post meridiem的缩写意为“下午)。a.m.或p. m.前假设是整点，用了a. m.或p. m后，不再用oclock，也不可加 “：00 ”。如：at 8 a. m.上午8点，at 5 p. m.下午5点。“点整时，用sharp。如: at nine oclock sharp九点整，at 23:00 sharp二十三点整。5)年龄表达 表示“岁 He
8、 is eighteen (years old). He is aged eighteen. He is at the age of eighteen. His age is eighteen. 表示“快满岁He will be eighteen years old. He is going on eighteen years old. He is getting on for eighteen.It will be his eighteenth birthday. 表示“不满岁He is barely/nearly/almost eighteen. He is not quite/yet e
9、ighteen.He is under/below eighteen.表示“已经岁可用以下方法表示：He is past/over/above eighteen.He is more than eighteen.He has turned eighteen.表示大概年龄时用“in ones +基数词复数形式结构。a.从十三岁到十九岁，用in ones teens . b.二十岁以上就用in ones twenties/thirties/forties/fifties /nineties，还可以借助early，middle，late来表达得更明确一些。 1记忆口诀，基数词变为序数词一二三要单独记
10、：one-first, two-second, three-thirdth要从四加起：four-fourth, five-fifth,.eight少个t：eight- eighthnine去掉e：nine-ninthve用f来代替：five-fifth, twelve-twelfthty变成tie：twenty-twentieth表第“几十几，基数加序数记心里：twenty-onetwenty-first2)序数词在句中主要作定语，一般情况下序数词前要加定冠词。Monday is the second day of a week.3)序数词前有时加不定冠词，表示“又一、再一，相当于anothe
11、r。 Would you like a second cup of tea?I had a fourth apple.我(吃了三个苹果后)又吃了一个苹果。4first, second等有时可表示一批人或物。 The first milu deer came from China in the 1860s. 最早的麋鹿是在十九世纪六十年代来自中国的。5有时序数词作状语，不加冠词。 He came out first in the contest. 他在比赛中得第一名。6first, second等在用来指“冠军、亚军等获胜名次时也常不加冠词。 He is first.他是冠军。四.百分数、分数、
12、小数的构成及用法1)百分数：基数词加百分号percent: 89%eight-nine percent2)分数：分子基数词，分母序数词。分子大于1，分母用复数。分子与分母用连字符连接。 1/3: one third, 2/5: two fifths3)带分数：基数词 + and +分数表达：5 6/7 : five and six-sevenths注意 1/2: a half, one half 1/4: one-fourth, one /a quarter 3/4: three quarters 1/3: a third(33.33r %读作 thirty-three point three
13、 three recurring percent)3小数：小数点读作“point，数字一律用基数词 1.45: one point four five4)通常分数、百分数、小数做定语。“分数百分数of +名词作主语时谓语动词是根据名词确定的，名词为单数动词即用单数，名词为复数动词即用复数动词。 50% apples are here. One third apple is eaten.one and a half后名词用复数，谓语动词一般用单数，不过事实上也可用复数。五. 加减乘除运算表达4 + 48：Four plus/added to four equals eight. Four and
14、 four are eight.734： Seven minus three is four. Three from seven leaves four.8864：Eight multiplied by eight is sixty -four. Eight times eight is sixty -four.2045：Twenty divided by four is five. Four into twenty goes five.六、倍数表达 表示倍数时，一倍用once，两倍用twice，三倍以上用“基数词+times。 1.常用句式：.times+ 形容词/副词的比拟级than.ti
15、mes as+形容词/副词原级+as+.“是长/高/宽的几倍 Li Ming runs twice faster than Lily.The river is three times longer than that one.= The river is three times as long as that one.Our classroom is four times as big as yours. = Our classroom is four times bigger than yours. The new building is four times the size of the
16、 old one1)“.times as many/much + n. + as + n.或“.times as much/many as + n. We have produced twice as many cars this year as we expected. 我们今年生产的汽车是预期的两倍。 There are four times as many books in our library as in theirs. 我们图书馆的书是他们图书馆的四倍。 The price of this product is twice as much as that of the previo
17、us one.该产品的价格是前一种的两倍。2) .times +more+名词+than+被比拟对象 He earns five times more money than he did ten years ago. 他现在挣的钱是十年前挣的五倍。3) .times +that of +被比拟对象 The size of the newly broadened square is four times that of the previous one. 新扩建的广场为以前的四倍大。The hospital charges three to five times that of ordinary
18、 ones 这家医院的收费是一般医院的三至五倍。4) .times + what从句The worlds population has grown to more than six times what it was in 1800. The figure is now approaching 6.5 billion people. 目前的世界人口与1800年相比已经增长到那时的六倍多，这个数字现在将近65亿。The price of the meat is now double/twice what it was last year. 现在的肉价是去年的两倍。5) .times +over或
19、up to The grain output in that province is twice over that of . 那个省的粮食产量是的两倍。 He is three times up to your age.他的年龄是你的三倍。6) .times +compared with+被比拟对象 The number of computer imports has increased 4 times compared with last year.计算机的进口量与去年相比增加了四倍。7)用分数、百分数来表示倍数。 The box is one-third bigger than that
20、 one. 这个盒子比那个盒子大三分之一。 Last year the output value of industry was 30 percent higher than that of .去年工业产值比增长了30%。 Im twice/double his age. 我的年龄是他的两倍。 The top-brand clothes are often sold as double the normal price here. 这里名牌衣服的售价经常比正常的售价高一倍。 Ive paid five times the usual price for the stamp. 我出了五倍于往常的
21、价格买这枚邮票。七、模糊概数表达法 绝大多数数词在指明事物的数目时，是不考虑自身的数的，但有些数词也有单数和复数形式。1.当hundred，thousand，million，billion前面有基数词时，用单数形式，词尾不加-s；前面有many， several，a few修饰时，仍用单数形式：several billion years 2.表示概数时，用ten, hundred, thousand, billion的复数形式加of,后面接复数名词。 thousands of lakes and forests3.强调数目众多时，可将tens, hundreds, thousands等用of,
22、 and或upon连接。tens of thousands of几万hundreds of thousands of几十万hundreds and hundreds of成百上千的thousands upon thousands of成千上万的4.dozen和score表示具体数目，也可表示模糊概数1)dozen和score表示具体数目与基数词连用时,dozen和score用单数形式。 two dozen pencils, three score years2)dozen表示具体数目时，不加-s也不用of: two dozen eggs。但后接代词、指示代词these/those等或所接的名词
23、前有限定词，就要加of: a dozen of these books一打这样的书, a dozen of us 我们中十二个人3) score表示具体数目时，不加-s，但可用of。 a score of eggs二十个鸡蛋 ten score of books 200本书4) dozen和score表示模糊概数时，加-s并加of。dozens of people几十个人 scores of times几十次八、约数表达法1.“许多；很多；大量的表达 在英语中，表示“许多，很多，大量含义的单词除了many和much以外，还有许多较常用的词组。1)只接可数名词复数的有several, (a go
24、od/great)many, hundreds of, a (large/good/great) number of, numbers of, few, a few, quite a few, not a few等。2)只接不可数名词的有little, a little, qute a little, an amount of, amounts of, a good/great deal of, a large sum of等。3)既可接可数名词复数也可接不可数名词的有some, any, all, none, enough, plenty of, a lot of, lots of, a (
25、large) quantity of, quantities of, a diversity of, diversities of, a variety of, varieties of, a world of, a wealth of等。“多于，超过用more than或over“少于用less than“或以上用or more Literally，multimedia means two or more media. 从字面上看，多媒体是指两种或两种以上的媒体。“或以下用or less The whole procedure will take perhaps only five minu
26、tes or less. 整个过程只需5分钟甚至更少的时间。“大约用about, around, some等。 Horseracing can be traced to the Olympic Games of about 600 BC. 赛马可追溯到大约公元前600年的奥运会。 Some 844 animals and plants have disappeared in the last 150 years. 大约有844种动植物在过去的150年里消失了。 I need around 300 dollars.我需要300美元左右。“左右用or so Please leave us for
27、five minutes or so，we have some private business to deal with. 请你先回避五分钟左右，我们有些私事要处理。九、 数词的特殊用法“每隔；每逢的含义，在基数词后用复数可数名词，在序数词后用单数可数名词。结构有四个：a. “every other/second +单数名词 表 “每隔一 Please write on every other line.请隔行书写。b. “every +基数词+复数名词 He comes here every four days.他每隔三天来此一次。c. “every +序数词+单数名词 He comes
28、here every fourth day.他每隔三天来此一次。d. “every few +复数名词 Please plant a tree every few meters.请每隔几米载一棵树。2.基数词可用来构成复合形容词。1)基数词+名词：ten-minute十分钟的 two-thousand-word两千词的2)基数词+名词的-ed形式 five-storied五层的, one-eyed 独眼的3)基数词+名词+形容词 five-month-old五个月大的, six-meter-long六米长的 a month or two一两个月，leave by ones and twos零零
29、落落地离开，in twos and threes三三两两地 Ten to one youll miss your flight. 你很可能要赶不上班机了。 Shes all at sixes and sevens about what to do. 她心里七上八下，不知该怎么办。十、其它1)固定用法 at sixes and sevens乱七八糟 one at a time一次一个地 one by one一个一个地 by the dozen以打计 by the hundred以百计 in tens十个十个地 in five hundreds五百五百地2)表示比例可用in, out ofone in/out of ten十个中的一个one in a thousand千万次中的一次十一、编码的表示法 在表示有顺序号的事物时可用基数词，也可用序数词。如数字较长，防止使用序数词。序数词放在名词前, 并加定冠词；基数词放在名词后，名词不加冠词。lesson one, the first lesson , Room 521, bus No. 2