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 St. Johns River. It gives a broad overview of the river without going into details. This follows the rule of Topic Sentence. Why other lines are not chosen? The other paragraphs are not chosen because they do not stand alone. For example, Paragraph 2 starts with "The earliest people..." which needs context. Paragraph 3 starts with "It was Spanish missionaries..." which also needs prior information. Paragraph 4 starts with "The mission was named..." which refers back to the mission without introducing it first.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the information about the river and the mission. It gives the name of the mission, which is the final detail in this topic. This follows the rule of Summary Style.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it continues the topic of the river. It gives information about the people who lived near the river. This follows the rule of Logical Order.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects to Paragraph 2 because it shows what happened after the Paleo-Indians. It talks about Spanish missionaries, which is a logical next step in the history of the river. This follows the rule of Logical Order.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because it gives more detail about the mission mentioned in Paragraph 3. It explains the name of the mission, which is a specific detail following a general statement. This follows the rule of Broader to Specific Strategy.