First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of technology having both good and bad sides. It sets the stage for the discussion without needing any prior context. This follows the rule of Topic Sentence. Why other lines are not chosen? The other paragraphs are not chosen because they do not stand alone. For example, 'For example, mobile phone;' starts with a phrase that needs more context. 'Someone driving a car and calling, causing an accident or hazard;' is a specific case and cannot be the first line. 'But we cannot deny the benefits of science and technology;' uses 'but' which shows it is not an independent statement.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the discussion. It summarizes the main idea that technology has both benefits and drawbacks. This follows the rule of Conclusive Words.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it gives a specific example of technology, which is a mobile phone. This follows the Broader to Specific Strategy.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 continues from Paragraph 2 by explaining a situation involving a mobile phone. This shows a logical order where the example leads to a specific case.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 contrasts with Paragraph 3. It shows that while there are dangers, there are also benefits. This follows the Contrast rule.