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。
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。
Based on the quality of linear operation about indefinite integral, the article puts forward an indefinite integral principle of making linear combination and reducing power of integrand.
从不定积分的线性运算性质出发，给出了计算不定积分的被积函数线性组合化、降幂的积分原则，并结合实例分析了这一原则在不定积分计算中的指导作用。
Based on the quality of linear operation about indefinite integral, the article puts forward an indefinite integral principle of making linear combination and reducing power of integrand.
从不定积分的线性运算性质出发，给出了计算不定积分的被积函数线性组合化、降幂的积分原则，并结合实例分析了这一原则在不定积分计算中的指导作用。
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