A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of planning a charity event. It sets the stage for what will follow without needing any prior context. It uses a broad overview to explain the importance of forming a team before getting into details. Why other lines are not chosen? The other paragraphs are not chosen because they do not stand alone. For example, Paragraph 2 starts with "Securing sponsors..." which needs context about the team first. Paragraph 3 uses "Detailed planning..." which assumes the team is already formed. Paragraph 4 and Paragraph 5 also refer to actions that come after the team is formed.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the whole process of organizing a charity event. It reflects on what happens after the event, which is a natural conclusion to the topic.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it continues the idea of planning. After forming a team, securing sponsors is the next logical step. This shows a logical order of actions needed for the event.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 follows Paragraph 2 because after securing sponsors, detailed planning is needed. This shows a clear progression from funding to planning, which is a logical order.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because after planning, promoting the event is the next step. This shows a logical order of actions, moving from planning to promotion.
• Pair 4 (Paragraph 4 → Paragraph 5): Paragraph 5 follows Paragraph 4 because after promoting the event, the next step is to gather feedback after it concludes. This shows a logical order from promotion to evaluation.