A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first because it introduces Ottawa and its importance as the capital of Canada. It gives a broad overview of the city and does not need any other sentence for context. It does not use any pronouns or definite articles that refer to previous information. Why other lines are not chosen? Paragraph 2 starts with 'Today,' which makes it dependent on the context of time. Paragraph 3 starts with 'The Rideau Canal,' which uses 'the' and assumes prior knowledge. Paragraph 4 starts with 'In summer,' which also depends on the context of seasons.

Concluding sentence: Why this is the last line? This paragraph is the last because it summarizes the activities related to the Rideau Canal. It gives a clear conclusion about what happens in the canal during different seasons.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it continues to talk about Ottawa. It uses the connector 'Today' to show that it is still about the same city. This shows a logical order of ideas.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects to Paragraph 2 because it gives more specific information about Ottawa. It talks about the Rideau Canal, which is an important part of the city. This shows a broader to specific strategy.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because it gives details about the Rideau Canal. It explains what people can do in the canal during different seasons. This shows a logical order of ideas.