A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first because it introduces the main topic of national parks. It gives a broad overview of what the text will discuss. It does not use any words that need prior context, making it clear and independent. Why other lines are not chosen? Paragraph 2 starts with 'These protected areas', which uses a pronoun that refers back to something not yet mentioned. Paragraph 3 starts with 'Whether you're hiking', which is not a general statement. Paragraph 4 starts with 'It's a magical place', which also uses a pronoun and does not introduce the topic.

Concluding sentence: Why this is the last line? This paragraph is the last because it wraps up the ideas presented in the text. It gives a final thought about the beauty of national parks, using words like 'magical' and 'wonders' to conclude the discussion.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it continues the topic of national parks. It uses the phrase 'These protected areas' to refer back to 'national parks', showing a clear link.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects to Paragraph 2 because it gives examples of what can be found in these protected areas. It shows a logical order from the general statement about wildlife to specific activities people can enjoy.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because it summarizes the experience of visiting national parks. It uses the phrase 'It's a magical place' to conclude the ideas about the beauty and enjoyment found in nature.