A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of the text. It gives a broad overview of how the digital era has changed music. It does not use any pronouns or definite articles that need prior context. Why other lines are not chosen? Paragraph 2 starts with "Specifically," which is a conjunction. Paragraph 3 starts with "Furthermore," which is also a conjunction. Paragraph 4 starts with "However," which is another conjunction. All these words show that these sentences depend on previous information.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the discussion. It shows the challenges that come with the changes in music. It gives a final thought on the topic.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects with Paragraph 1 because it gives more details about the changes in music. It uses the word "Specifically" to show that it is explaining the topic further.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects with Paragraph 2 because it continues to explain how technology helps artists. The word "Furthermore" shows that it adds more information about the topic.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects with Paragraph 3 because it shows a contrast. It starts with "However," which indicates that there are problems despite the benefits mentioned in Paragraph 3.