1.A是B的N倍大/长…(或者A比B大/长…N-1倍)
一般有以下两种英语表达方法;
(1) A is N times as large/long (形容词/副词原形) as B. Eg: Asia is four times as large as Europe.
(2) A is N times larger/longer（形容词/副词比较级）than B. Eg: Asia is four times larger than Europe.
(3) A is N times the size/length (形容词/副词的名词形式) of B. Eg: Asia is four times the size of Europe.
以上三句例句的中文翻译均为：亚洲是欧洲的四倍大，或者亚洲比欧洲大三倍。
2. by 和to
(1) 动词+ by + 倍数/百分数/数词
Eg: The production of grain has been increased by four times this year.
今年粮食产量增加了四倍。
(2) 动词+ to + 数词
Eg: Last year profits rose to $201 million.
去年利润增长到2亿零100万美元。
3. by a factor of
词组by a factor of 在《朗文双解》中的解释为"if something increases or decreases by a factor of N, it increases or decreases by N times."以N倍的系数增加或减少。这个解释表达不是很明确，现在把它分成以下两种情况来分析：
(1)表示增加含义时
Increase/grow…by a factor of N times 增加到N倍，或者增加了N-1倍
Eg: The output of diesel oil for farm use has been increased by a factor of five times these years.
这些年来，用于农业生产的柴油产量增加了四倍。
(2)表示减少含义时
Decrease/fall…by a factor of N times 减少到1/N，或者减少了(N-1)/N。
Eg: The production has decreased by a factor of three times as against 1977.
总产量减少到1977年的三分之一。
（来自：http://www.chinaenglish.com.cn）
