We already have ______ pencils, but we need two ______ pens.

A. dozen of, dozen                          B. dozens of, dozens

C. dozens of, dozen                        D. dozens of, dozen of

【分析】此题最佳答案为C。关于dozen的复数是否加词尾-s的问题比较复杂,大致原则是:

(1) 当它与具体数字连用时,既不加复数词尾-s,也不后接介词of。尽管有的词书也有 two dozen of 这样的用例,但这已属过时用法,在考试中应避免,如1992年全国高考有一道单项选择题就认为two dozen of为错误选项:

Shortly after the accident, _____ police were sent to the spot to keep order.

A. dozens of                B. dozens                   C. dozen of                    D. dozen             [D]

(2) 当它不与具体数字连用,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,此时可将dozens of(许多,几十)视为习语。如:

I’ve been there dozens of times. 我去过那儿几十次。

She’s got dozens of boy-friends. 她的男朋友很多。

下面一例中的dozens加了复数词尾-s也属为似情况:

Pack them in dozens. 按打装袋吧。

(3) 当与 a few, several 等数目不很具体的词连用时,加不加复数词尾-s均可,但需注意:不加复数词尾-s时,其后的介词of可以省略;加词尾-s时,其后介词 of不能省略。如:

several dozen (of) pencils=several dozens of pencils几打铅笔(from www.youthemE.CN)

注:英语较少使用many dozen的说法,要表示类似意思可用dozens of。

(4) 当它后面的名词受 the, these, those 等特指限定词修饰时,或其后的接的是us, them这样的人称代词时,则此时必须用介词 of。如:

two dozen of these eggs 两打这种鸡蛋

three dozen of them 它们中的3打

注:score, hundred, thousand, million等也具有以上类似用法。