There was _ article about pollution in _ paper.

Explanation

There was an article about pollution in the paper.Here's why each article is used:"An" before "article": The indefinite article "an" is used before "article" because "article" starts with a vowel sound."The" before "paper": The definite article "the" is used before "paper" because it refers to a specific newspaper that both the speaker and the listener are likely familiar with or have discussed previously.