First sentence: Why this is the first line? This paragraph is the first because it introduces the main topic, which is the international dateline. It gives a broad overview of what the dateline is without going into details. It does not use any pronouns or definite articles that refer to previous information. Why other lines are not chosen? Paragraph 2 starts with "The date line" which uses the definite article "the" and assumes prior knowledge. Paragraph 3 starts with "The same problem" which uses the definite article and refers back to something not yet mentioned. Paragraph 4 starts with "For example" which suggests it is giving an example and not introducing a new idea. Paragraph 5 starts with "The apparent paradox" which also assumes prior context.

Concluding sentence: Why this is the last line? This paragraph is the last because it provides a solution to the problems discussed in the earlier paragraphs. It wraps up the discussion by explaining how the confusion can be resolved.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it explains why the date line is important. It uses the Logical Order rule, as it follows the introduction of the dateline with a statement about its necessity.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects to Paragraph 2 because it gives an example of the confusion that can happen due to the date line. This follows the Broader to Specific Strategy, where the general statement about confusion is followed by a specific example.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because it discusses another situation where the same confusion happens. This follows the Logical Order rule, as it continues the discussion of problems related to the date line.
• Pair 4 (Paragraph 4 → Paragraph 5): Paragraph 5 connects to Paragraph 4 because it explains how to solve the problem mentioned in the previous paragraph. This follows the Cause and Effect Relationship rule, as it shows the solution to the problem.