n. 打, 十二个a. 一打的相关词组: be six of one and half a dozen of the other

• dozen, score的用法
  
  dozen, score的用法
  
  dozen的意思是“一打”“十二个”，score的意思是“二十”，它们在用法上具有以下共同特点，使用时需注意：
  1. 与具体数字连用时，不加复数词尾 –s；若后接名词，通常也无需用介词of。如：
  I’d like three dozen altogether. 我想一共要3打。
  He has lived here for two score years. 他已在这儿住了40年。
  偶尔也可见到受具体数字修饰的dozen, score后接 of，但惯用法认为省略 of则常见。
  2. 若不与具体数字连用，而是表示不确定的泛指数时，则不仅要加复数词尾 -s, 而且要后接介词of，然后才能接名词。如：
  There were dozens of people there. 那里有许多人。
  I have heard of that scores of times. 那件事我已听过很多遍了。
  3. 当与a few, several, many等数目不很具体的词连用时，带不带复数词尾 -s均可，但是注意：

billion/million/millionaire/thousand/hundred/dozen/score
记忆：
1. billion bill-ion联想Bill Gates, 世界亿万富翁；billion, 十亿
2. million mill-ion 百万
3. millionaire n. 百万富翁 Nowadays a millionaire is no longer an attraction in newspapers. 今天百万富翁不再是报纸上的亮点。
4. thousand千 Thousands of people went to the street to show their call for peace. 成千上万的人走上街头呼唤和平。
5. hundred 百
6. dozen音“打”， 一打，十二 We brought home two dozen beer. 我们带了两打啤酒回家。
7. score sc两个“十”， 二十， 得分 He bought two score of apples yesterday.他昨天买了四十个苹果。
另类阅读：
Beer is sold by the dozen here. I want five score of bottle, but I have only one hundred yuan. If you can lend me one million, I can have thousands of yuan left. I could say billion, for it is impossible.