A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first line because it introduces the main topic of poverty and unemployment. It sets the stage for the discussion without needing any prior context. It gives a broad overview of the situation. Why other lines are not chosen? Paragraph 2 starts with "It was initially thought" which makes it dependent on prior information. Paragraph 3 starts with "Therefore" which shows it is linked to a previous idea. Paragraph 4 starts with "It was not until late" which also indicates it is not independent. All these sentences do not stand alone.

Concluding sentence: Why this is the last line? This paragraph is the last line because it concludes the discussion by providing a new insight into the causes of unemployment. It wraps up the ideas presented in the previous paragraphs and shows a change in understanding.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): This pair connects because Paragraph 2 explains the thoughts about unemployment that follow the introduction in Paragraph 1. It uses the Logical Order rule, as it continues the discussion about the reasons for rising unemployment.
• Pair 2 (Paragraph 2 → Paragraph 3): This pair connects because Paragraph 3 explains the conclusion drawn from the ideas in Paragraph 2. It uses the Cause and Effect Relationship rule, as it shows how the thoughts about workers' traits led to the belief that unemployment was an individual issue.
• Pair 3 (Paragraph 3 → Paragraph 4): This pair connects because Paragraph 4 presents a new understanding that contrasts with the consensus in Paragraph 3. It uses the Contrast rule, as it shows a shift in thinking about the causes of unemployment.