The content of annotations can be roughly divided into three categories:
1. Note: When reading, if you encounter unfamiliar or difficult words, look up the dictionary and reference books, find out the meaning, point out the source and write them in the blank.
2. Abstract: Think while watching, summarize the central idea in concise language, grasp the context of the article, and prompt the language characteristics.
3. Comments: There will be various ideas, opinions and questions when reading, which can be written in the blank space.