A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic, which is the hydrologic or water cycle. It gives a broad overview of what the text will discuss. It does not use any pronouns or definite articles that refer to previous information. Why other lines are not chosen? Paragraph 2 starts with "In simple terms," which is a transitional phrase. Paragraph 3 uses "The path of this complex cycle," which refers back to the cycle, so it is not independent. Paragraph 4 starts with "The latter part of the cycle," which also refers back to the cycle, making it not independent.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the discussion about the water cycle. It explains the final part of the cycle, which is precipitation. This gives closure to the topic introduced in the first paragraph.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it continues the discussion about the water cycle. It explains the path of the cycle, which logically follows the introduction of the cycle in Paragraph 1. This shows a logical order.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects to Paragraph 2 because it explains what happens in the water cycle. It gives specific details about the process of evaporation and precipitation, which follows the general description of the cycle's path in Paragraph 2. This is a broader to specific strategy.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because it describes the precipitation process, which is the last part of the water cycle. It follows the explanation of how water returns to Earth, showing a logical order.