有人问： 有一个句子是这样的：

(1)Journalism historians have tried to date the first newspaper interview — some credit James Gordon Bennet in 1836; others, Horace Greanley in 1859 — but it is less important to identify an individual inventor than to recognize that a practice largely unknown as late as 1860 was familiar, and controversial, a decade later.

这里为何不用the practice以指代前面提到的newspaper interview，却用了a practice?

这里用a practice而不用the practice，就是将特定的事物泛化了。泛化之后它就变为泛指的比较客观的事物了。再如：

(2)A book may help you a lot with your writing.（从上文看这里的a book就是作者所谈的那本书）

(3)The only decent restaurant in a city once filled with fine dining places was La Torre, ...（a city指上文所说的Havana）

同样，用不定冠词a也可将特定的人加以泛化，如：

(4)What is a man to do in such a case?（从上文看这里的a man实际上指I）