The paragraph is followed by an incomplete phrase or sentence which summarizes the main idea of the paragraph. Choose the missing words of the phrase or sentence.

Every culture has specific rules of courtesy and certain words for special situation. What are considered polite manners in one culture might be terribly rude in another. One of the difficulties of learning a foreign language is learning what is considered polite and rude in the culture of that language.
Using language （） within its culture.