A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of medical education in Manchester. It gives a clear starting point with a specific date and person, Joseph Jordan. This follows the rule of Topic Sentence, as it sets up the main topic without going into details. Why other lines are not chosen? The other paragraphs are not independent. For example, Paragraph 2 starts with "Previous lecture courses" which refers back to earlier information, so it is not independent. Paragraph 3 starts with "Jordan, however," which uses a pronoun that refers back to Jordan, making it not independent. Paragraph 4 starts with "In London," which also refers to a specific place and context, so it is not independent.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the discussion about medical schools. It gives a final overview of how schools in London and the provinces operated. This follows the Summary Style rule, as it brings together the earlier points about medical education.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it gives background information about earlier medical education. This follows the Broader to Specific Strategy, as it provides a general idea of previous courses before focusing on Jordan's school.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects to Paragraph 2 because it talks about what Jordan offered in his school. This follows the Logical Order rule, as it shows how Jordan's offerings are a continuation of the discussion about medical education.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because it expands on the topic of medical schools. This follows the Topic Example rule, as it gives more details about how medical schools operated in different areas.