高考热点专题：倍数表达法.doc

倍数表达法倍数表达法是高中英语教学的重点，也是历届高考的热点。当我们要表达甲是乙的几倍时，通常用下面三个句型来表示：1. “A+倍数+形容词或副词的比较级+than+B”，表示“A比B大（长、高、宽等）多少倍”。如：This rope is twice longer than that one. 这根绳子是那根绳子的两倍长（比那根绳子长一倍）。This hall is five times bigger than our classroom. 这个大厅比我们的教室大四倍（是我们教室的五倍）。The car runs twice faster than that truck. 这辆小车的速度比那辆卡车快一倍（是那辆卡车的两倍）。2.“A+倍数+as+形容词或副词的原级+as+B”，表示“A正好是B的多少倍”。如：Asia is four times as large as Europe. 亚洲的面积是欧洲的四倍。This big stone is three times as heavy as that one. 这块大石头的重量是那块的三倍。The plane flew ten times as high as the kite. 那架飞机的飞行高度是那只风筝的十倍。3. “A+倍数+the size/height/length/width， etc+of+B”，表示“A正好是B的多少倍”。如：This street is four times the length of that one. 这条街是那条街的四倍长。This hill is four times the height of that small one. 这座山的高度是那座小山的四倍。除掌握倍数表达的三个常规句型外，我们更要注意的是其常规句型的变形及其特殊规律。一。 常规句型的变形1. “ times+more+名词（可数或不可数）+than+被比对象”。如：There are five times more books in our library than in yours. 我们图书馆里的书比你们图书馆多四倍。We have produced twice more grain this year than we did last year. 我们今年生产的粮食是去年的两倍。2. “ times as many/much+名词+as+被比对象”。如：There is four times as much water in this pot as in that one. 这个壶里装的水是那个壶里的四倍。There are six times as many students as we expected. 学生数量是我们预期的六倍。3.“ times+over+被比对象”。如：The grain output in that village is twice over that of 2002. 那个村的粮食产量是2002年的两倍。4. “ times+that+of+被比对象 ”。如：In this workshop， the output of July was 4.5 times that of January. 这个车间7月份的产量是1月份的4.5倍。5. “times+compared with+被比对象”。如：The number of the students in our school has increased 4 times compared with 1980. 我们学校的学生人数比1980年增加了三倍。6. “times+what+从句”。如：The production is now three times what it was ten years ago. 现在的产量比十年前增加了两倍。二。 倍数/百分数（percent）+compared with/up on +被比对象。如：Our factory s output of TV sets in the first six months of this year was 10% up compared with last year. 今年头六个月我们厂电视机的产量与去年相比增加了10%.The industrial output of last year in our factory was 35% up on that of 2001. 我们厂去年的工业产量比2001年增加了35%.三。 用double表示倍数1. double用作形容词，表示“两倍的”。如：The production is now double what it was ten years ago. 现在的产量是十年前的两倍。2. double用作动词，表示“是的两倍。如：The output has been doubled in the past six years. 在过去六年中产量已经翻了一番。This brought a steady rise in the grain yield. In 2002 it nearly doubled that of 1980. 这使粮食产量不断增长，到2002年产量已经比1980年翻了一番。 倍数表达法是历届高考的热点。当我们要表达甲是乙的几倍时，通常可使用以下句型：1.倍数+as+形容词或副词的原级+as+其它。这种结构又常演变成下列两类：倍数+as+many+可数名词复数+as;倍数+as+much+不可数名词+as。如：There are seven times as many people as I expected.是我预料的人数的七倍。There is five times as much coffee in this glass as in that one.这个杯子里的咖啡是那个杯子里的五倍。2.倍数+形容词（或副词）的比较级+ than+其它。如：The hall is five times bigger than our classroom.这个大厅的面积比我们教师大五倍。3.倍数+the size/height/length/width.etc.+of+其它。如：This road is six times the length of that one.这条路是那条路的六倍长。4.计量名词+of+名词+be+倍数+that+of+其它。如：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。5.倍数+what从句。如：The production is now three times what it was ten years ago.现在的产量是十年前的三倍。6.倍数+more+名词+than+其它。如：There are nine times more books in his bag than in yours.他书包里的书比你书包里的书多九倍。7.其它表达。如：Shes twice/double my age.她的年龄是我的两倍。The average income of the staff has been increased by 50 percent compared with last year.与去年相比，该单位职工的收入已增加了50%。He runs faster than me by three times.他跑得比我快三倍。考查方向1）倍数在句中的位置一般放在第一个as前面或比较级前面或名词前面。2）用times表示倍数时，一般只限于表示包括基数在内的三倍或三倍以上的数。表示两倍可以用twice或double,一倍用once.【重点归纳】除了我们初中所学的形容词的比较级的用法，本模块我们主要归纳几种句式结构：（一）含倍数的比较句型1.倍数+as+形容词原级+as。如：This bridge is three times as long as that one.His room is twice as big as mine;in other words,mine is only half as big as his.【特别提醒】“asas”中间加入名词的句式：倍数+as+形容词+a/an+可数名词单数+as倍数+as+形容词+可数名词复数/不可数名词+as。如：Last year my brother twice as big a new house as mine.He has collected more than three times as many stamps as I (have).I spent twice as much time on my studies as you did.【难点点拨】该结构的省略：通常省略形容词后面的名词及比较的部分。如：I have to transfer(转乘）buses so I spend twice as much (money as others)for the bus every day.2.倍数+形容词比较级+than。如：This street is four times shorter than that one.Fear of danger is ten thousand times more terrifying than danger itself.【特别提醒】倍数+形容词比较级+名词+than。如：He earns five times more money now than he did ten years ago.There are three times more books in our library than in yours.3.倍数+the+名词（如size,height,weight,length,width,depth等）+of。如：This well is three times the depth of that one.4.另外，请注意下面两种说法：（1）倍数+what从句。如：The length of the road is four times what it was three years ago.(2)倍数+that of+被比较对象。如：Airmail charges almost twice or three times that of a normal mail.(二）其它句式1.比较级+and+比较级表示越来越。如：Things are getting better and better every day.Our country is becoming more and more beautiful.2.the+比较级，the+比较级表示“越，就越”。如：The more you have, the more you want.The more a man knows, the less he knows he knows.【知识扩展】在形容词比较级前可以加a little,a bit,a lot,no,any,much,far,even,still等副词（组），表示程度的加深。如：The result is much better than we expected.Actually,health is far more important than wealth.5