A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces Stephen Hawking. It gives basic information about him, like his name and when he was born. This is an introductory sentence. It does not need other sentences to understand it. Why other lines are not chosen? Paragraph 2 starts with "Despite" which is a conjunction. Paragraph 3 starts with "Hawking's" which is not general. Paragraph 4 starts with "His" which is a pronoun. All these do not stand alone without context.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it sums up Hawking's life and work. It shows the overall effect he had on the world. It wraps up the main ideas about him.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): This pair connects because the second paragraph explains more about Hawking. It shows how he overcame his disease to make important discoveries. This is a cause and effect relationship.
• Pair 2 (Paragraph 2 → Paragraph 3): This pair connects because the third paragraph gives an example of Hawking's contributions. His book shows how he shared his ideas with many people. This is a broader to specific strategy.
• Pair 3 (Paragraph 3 → Paragraph 4): This pair connects because the fourth paragraph talks about the impact of Hawking's work. It shows how his book and life affected science and culture. This is a logical order.