指代

A. 相同内容单元
Units of Identical Contents

1. Unit of Summarized Content followed by Unit of Elaborated Content
2. Unit of Elaborated Content followed by Unit of Summarized Content (the pair above reversed)
3. Unit of Vague Content followed by Unit of Illuminated Content
4. Unit of Doubtful Content followed by Unit of Confirming Content
5. Unit of Main Content followed by Unit of Concluding Content