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 talks about how feeding preferences affect migration. This is a general statement that sets the stage for the following paragraphs. It does not use any specific details or references to other ideas, which makes it a good opening line. Why other lines are not chosen? The other paragraphs are not chosen because they do not stand alone. For example, Paragraph 2 starts with 'The wildebeests,' which refers to a specific group and needs context. Paragraph 3 uses 'The other species,' which also needs prior information. Paragraph 4 starts with 'But when,' which shows it is continuing a thought. Paragraph 5 uses 'The sequence,' which assumes knowledge of what sequence is being discussed.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the main ideas. It gives a final point about how migration is related to body size. This helps to conclude the discussion about migration and feeding preferences.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it gives an example of how feeding preferences affect migration. The word 'follow' shows that wildebeests are part of the discussion about migration.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects to Paragraph 2 because it continues the idea of migration. The phrase 'do likewise' shows that other species also follow similar patterns, linking the two ideas.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because it explains what happens when there is rain. The word 'But' shows a contrast and introduces a new situation that affects migration.
• Pair 4 (Paragraph 4 → Paragraph 5): Paragraph 5 connects to Paragraph 4 because it explains the order of migration. The word 'sequence' refers back to the order mentioned in Paragraph 4, showing a clear link between the two.