A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of antibiotic resistance. It gives a broad overview of the issue without going into details. This follows the rule of Topic Sentence. Why other lines are not chosen? The other paragraphs are not chosen as the first sentence because they do not stand alone. For example, Paragraph 2 starts with 'Overuse' which needs context. Paragraph 3 uses 'This development' which refers back to something. Paragraph 4 talks about strategies but does not introduce the topic.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the discussion by providing solutions. It follows the Conclusive Words rule, as it gives a clear end to the topic of antibiotic resistance.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it explains why antibiotic resistance is a concern. It uses the Logical Order rule, showing how the first sentence leads to the details in the second.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects to Paragraph 2 because it shows the effect of antibiotic resistance. It uses the Cause and Effect Relationship rule, explaining the danger that comes from the misuse of antibiotics.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because it talks about solutions to the problem mentioned in the third paragraph. It follows the Broader to Specific Strategy, moving from the problem to the strategies to fix it.