First sentence: Why this is the first line? This paragraph is the first line because it introduces the main topic of the text, which is the rise in US gas and oil production. It gives a broad overview of the situation without needing prior context. It does not use any pronouns or definite articles that refer to previous information. Why other lines are not chosen? Paragraph 2 starts with 'In particular,' which is a transitional phrase. Paragraph 3 starts with 'The energy companies,' which uses a definite article and assumes prior knowledge. Paragraph 4 starts with 'Those who oppose,' which also uses a pronoun. Paragraph 5 starts with 'At the moment,' which is a time reference and does not stand alone.

Concluding sentence: Why this is the last line? This paragraph is the last line because it wraps up the discussion. It shows that the debate continues and reflects the overall theme of the text, which is about the conflict between different views on oil and gas production.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): This pair connects because Paragraph 2 gives specific details about how the increased output happened. It follows the broader statement in Paragraph 1, showing a logical order from general to specific.
• Pair 2 (Paragraph 2 → Paragraph 3): This pair connects because Paragraph 3 explains the benefits of the new techniques mentioned in Paragraph 2. It shows a logical order where the specific methods lead to the claims made by energy companies.
• Pair 3 (Paragraph 3 → Paragraph 4): This pair connects because Paragraph 4 presents the opposing view to the claims made in Paragraph 3. It shows a contrast between the benefits and the concerns about environmental consequences.
• Pair 4 (Paragraph 4 → Paragraph 5): This pair connects because Paragraph 5 summarizes the ongoing debate between the two groups. It logically follows the discussion of opposing views in Paragraph 4.