上海新东方夏令营英语学习：

　　(一) a is n times as great(long, much，…)as b. (①)

　　a is n times greater (longer, more，…)than b. (②)

　　a is n times the size (length, amount，…)of b. (③)

　　以上三句都应译为：a的大小(长度，数量，……)是b的n倍.

　　e.g. this book is three times as long as (three times longer than/three times the length of)that one.

　　这本书的篇幅是那本书的3倍(即长两倍)。

　　注：当相比的对象b很明显时，than (as，of) b常被省去。

　　(二) increase to n times(④)

　　increase n times／n-fold(⑤)

　　increase by n times(⑥)

　　increase by a factor of n(⑦)

　　以上四式均应译为：增加到n倍 (或：增加n-1倍)。

　　e.g. the production of integrated circuits has been increased to three times as compared with last year. 集成电路的产量比去年增加了两倍。

　　e.g. the output of chemical fertilizer has been raised five times as against l986. 化肥产量比1986年增加了4倍。

　　e.g. that can increase metabolic rates by two or three times. 那可使代谢率提高到原来的2倍或3倍(即提高1倍或2倍)。

　　e.g. the drain voltage has been increased by a factor of four. 漏电压增加了3借(即增加到原来的4倍)。

　　注：在这类句型中increase常被raise，grow，go/step up，multiply等词所替代。

　　(三) there is a n-fold increase/growth…(⑧)

　　应译为：增加n-倍(或增至n倍)。这个句型还有其它一些形式：

　　e.g. a record high increase in value of four times was reported. 据报道，价值破记录地增长了3倍。

　　(四) double (增加1倍)，treble(增加2倍)，quadruple(增加3倍)。(⑨)

　　e.g. the efficiency of the machines has been more than trebled or quadrupled. 这些机器的效率已提高了2倍或3倍多。

　　(五) 此外，英语中还有一种用again而不用倍数词来比较倍数的方法，如：

　　a is as much (large，long，…)again as b.(= a is twice as much (large，long，…)as b.(⑩)

　　应译为：a比b多(大，长，……)1倍。

　　a is half as much (large， 1ong，…)again as b.

　　(= a is one and a half times as much (large， 1ong，…)as b.)(11)

　　应译为：a比b多(大，长……)一半(即a是b的一倍半)。