A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of oral literature. It does not need other sentences for context. It gives a broad overview of what oral literature is. Why other lines are not chosen? Paragraph 2 starts with 'Stories' and refers to specific types of literature, so it is not independent. Paragraph 3 starts with 'Music' and needs context about oral literature. Paragraph 4 starts with 'Teaching' and refers to music, needing prior information. Paragraph 5 starts with 'Today' and refers to current music education, needing context.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the discussion about music education. It gives a summary of how things have changed and improved. The phrase 'Today' signals that this is the conclusion of the topic.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it continues the theme of literature. The phrase 'Stories and poetry' relates to the types of oral literature mentioned in Paragraph 1. This shows a logical order from the general idea of oral literature to specific examples.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects to Paragraph 2 because it discusses another form of oral tradition, which is music. The transition from stories and poetry to music shows a logical order of how different forms of oral communication were used.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because it explains the challenges of teaching music before notation. The mention of 'absence of written notation' in Paragraph 4 directly relates to the discussion of music in Paragraph 3, showing a cause and effect relationship.
• Pair 4 (Paragraph 4 → Paragraph 5): Paragraph 5 connects to Paragraph 4 because it shows the change in music education. The word 'Today' indicates a shift to the present, where notation systems have made teaching easier. This shows a logical order from past difficulties to current improvements.