A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first because it introduces the main topic of the text, which is about how ideas about history have changed. It does not refer to any previous information. It sets the stage for the discussion. Why other lines are not chosen? Paragraph 2 starts with "In theory," which is a transitional phrase. Paragraph 3 starts with "Historians must make decisions," which is specific and assumes prior knowledge. Paragraph 4 starts with "In doing so," which refers back to previous ideas. All these reasons make them not independent.

Concluding sentence: Why this is the last line? This paragraph is the last because it wraps up the main ideas. It shows how historians create narratives and how these narratives change. It uses conclusive words like "Inevitably" to signal the end of the discussion.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it gives a response to the idea in Paragraph 1. It uses the Connector strategy with "In theory, yes," showing that it is answering the question about whether writing history is straightforward.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 follows Paragraph 2 logically because it explains what historians do with the messy evidence. It uses the Logical Order strategy, as it shows the next step after discussing the evidence.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because it explains the result of the decisions historians make. It uses the Object Subject Strategy, where the object of Paragraph 3 (the decisions) becomes the subject of Paragraph 4 (the narratives created).
• Pair 4 (Paragraph 4 → Paragraph 5): This is the last pair, and it concludes the discussion about how narratives change over time. It summarizes the process of creating and updating narratives.