基数词如:ten、hundred,thousands,milion,dozen等与确切数字连用时,只能用单数形式,不加s. 如:eight hundred students 800个学生 但是在表示概数时,如“成千上万”等,基数词要加s,且与of 连用 如:hundreds of birds 数百只鸟 基数词可以表示书页、房间、邮政编码,住所等的编号 如:page 10 第十页bus 906 第906路公交车 表示几十岁,用“in+one's+数词复数” 如:he was already in his forties他已经40岁了 表示“年代”,用“in+the+年份复数” 如:in the 1940s 在20世纪40年代 序数词的用法
主语+谓语+倍数+as+adj/adv+as 例:i have three times as many as you .我有你三倍那么多。 主语+谓语+倍数+the size(amount,length...)of .... 例:the earth is 49 times the size of the moon. 地球是月球的49倍。 主语+谓语+倍数+形容词(副词)比较级+than.... 例:the grain output is 8 percent higher this year than that of last year今年的粮食产量比去年增加了8% 还可以用by+倍数,表示增加多少倍 例:the production of grain has been increased by four times this year今年的粮食产量比去年增加了8%