A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of personal savings. It gives a broad overview of why savings are important. It does not use any words that need prior context. Why other lines are not chosen? Paragraph 2 starts with 'They', which is a pronoun that refers back to something. Paragraph 3 starts with 'For example', which shows it is not independent. Paragraph 4 starts with 'Additionally', which is a connector and shows it is not independent.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the discussion about savings. It gives more information about how savings can be used in the future.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects with Paragraph 1 because it explains how personal savings help. The phrase 'They provide' shows that it continues the idea of savings.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects with Paragraph 2 because it gives an example of how savings help. The phrase 'For example' shows that it explains the previous idea.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects with Paragraph 3 because it adds more information about savings. The word 'Additionally' shows that it continues the discussion about savings.