In English, "a" and "an" are called the indefinite article, and "the" is called the definite article.

在英语中，“a”和“an”被称为不定冠词，“the”被称为定冠词。

We can't use the indefinite article with this noun.

我们不可以在这个名词前用不定冠词。

Indefinite article: used to indicate that a thing is not identified as unique.

不定冠词：用于指定不特定不唯一的东西。

There are in English two articles: the definite article and the indefinite article.

英语中有两个冠词，即定冠词和不定冠词。

Article 4. There are three different terms of validity of resident identity CARDS: 10 years, 20 years and an indefinite number of years.

第四条居民身份证的有效期限分为十年、二十年、长期三种。