This paragraph also has one sentence that does not belong, that is, which is not related to the main idea of the paragraph. Decide which one it is. Primary education is grades one through six. In primary schools, most students have the same teacher all day long, except for classes like music. Students have different teachers for each class, and classes meet five times a week.
Most students go to colleges and universities for two to four years, though some attend longer.
Japan also has three levels of education. The first sentence is the introduction. This paragraph is about the three parts of the American education system. Sentences 2-8 are the discussion. Sentences 2-3 explain what primary education is and gives some characteristics.