A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it asks a question that introduces the topic of negative thoughts before a presentation. It sets the stage for the discussion about fear and anxiety. This follows the rule of Topic Sentence because it introduces the main idea without needing prior context. Why other lines are not chosen? The other paragraphs do not qualify as the first sentence. For example, Paragraph 2 starts with 'I wouldn't be surprised,' which is not a general statement. Paragraph 3 uses 'Yet they become a problem,' which refers back to previous ideas. Paragraph 4 starts with 'If your negative thoughts make you unable,' which is conditional and does not stand alone.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it provides a solution to the issues discussed earlier. It wraps up the topic by suggesting ways to cope with negative thoughts, following the rule of Conclusive Words as it gives a clear ending to the discussion.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it continues the idea of negative thoughts. The question in Paragraph 1 leads to the statement in Paragraph 2, showing a logical order of thought.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 follows Paragraph 2 because it explains the consequence of negative thoughts. The phrase 'Yet they become a problem' shows a cause and effect relationship, linking the two ideas.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 as it gives a solution to the problem mentioned. It shows a logical order where the problem leads to the need for coping strategies.