a+序数词和the+序数词的区别

　　the：

　　art.指已提到或易领会到的人或事物;指独一无二的、正常的或不言而喻的人或事物;解说时用。

　　例句：

　　We put an ad in the local paper.

　　我们在当地报纸上登了一则广告。

　　I could come next week, or the week after.

　　我可能下周来，或者再下一周。

　　Much of the form was not applicable to me.

　　表格中很多部分不适用于我。

　　a：

　　art.(用于可数名词或单数名词前，表示未曾提到的)一(人、事、物);用于前有形容词或后有短语的不可数名词前;任何一;每一。

　　例句：

　　A number of measures were taken to alleviate the problem.

　　采取了一系列措施缓解这个问题。

　　She's a changed woman since she got that job.

　　她自从得到了那份工作，变得判若两人。

　　A free trade agreement would be advantageous to both countries.

　　自由贸易协定对两国都会有利。