A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of migration after World War II. It sets the stage for the discussion about Caribbean people in Britain. It does not refer to any previous information, so it is independent. Why other lines are not chosen? Paragraph 2 starts with 'From 1962,' which means it needs earlier context. Paragraph 3 starts with 'Prejudice and discrimination,' which assumes knowledge of the topic. Paragraph 4 starts with 'Today many of the half million,' which also needs earlier context.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the discussion about the Afro-Caribbean people in Britain. It summarizes the challenges they face, which is a fitting conclusion to the topic.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): The second paragraph connects to the first because it explains what happened after the migration. It shows a logical order of events, moving from migration to the rules that affected it.
• Pair 2 (Paragraph 2 → Paragraph 3): The third paragraph connects to the second because it talks about the people who came after the rules were made. It shows a broader to specific strategy, moving from the rules to the specific group of Afro-Caribbean people.
• Pair 3 (Paragraph 3 → Paragraph 4): The fourth paragraph connects to the third because it discusses the problems faced by the Afro-Caribbean people. It shows a logical order, moving from their background to the issues they face.