A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of creating a fitness routine. It sets up the main idea without going into details. It uses the phrase 'Establishing a personal fitness routine' which shows it is about starting a fitness plan. Why other lines are not chosen? Paragraph 2 starts with 'Once goals are set,' which means it needs information from another sentence. Paragraph 3 starts with 'Integrating a variety of exercises,' which is specific and not general. Paragraph 4 starts with 'As you progress,' which also needs prior context.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the ideas about fitness routines. It talks about reviewing and adjusting goals, which is a final step in the process.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it follows the logical order of steps in creating a fitness routine. After setting goals, the next step is to create a schedule.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 follows Paragraph 2 because after making a schedule, the next step is to include different exercises. This shows a broader to specific strategy.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because after integrating exercises, it is important to review and adjust your routine. This shows a logical order of progression.