For example, "Lesson 23 The Outbreak of the Civil War", this lesson is only two pages in the new textbook, with content on four pages, but when he reads the paragraphs, Li Shi would recall high school and college, as well as extracurricular reading and learning of related history, such as the causes and consequences of Chongqing, and at this stage, both domestically and internationally, the focus is on the attitudes and measures of America and the Soviet Union towards China, and so on.
Sometimes, when he found that he couldn't remember some details, he would look up online to settle all the questions, without any doubts before moving on to the next lesson.
During this time, due to searching a lot of historical information, Li Shi also discovered some treasure-trove websites, such as: All History, China Literature and History, and so on.