A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of writing an essay. It does not need another sentence for context. It sets up the theme of using outside sources. Why other lines are not chosen? The other paragraphs are not chosen because they do not stand alone. For example, "It can be helpful to quote..." starts with a specific idea and needs context. "But sometimes you need to explain..." starts with 'but', which is a conjunction. "For this, you need to paraphrase..." also needs context. "You can use paraphrasing..." uses 'you' which refers back to the reader, so it is not independent.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the main idea. It shows how paraphrasing helps in writing. It gives a final thought on the topic.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): This pair connects because the second paragraph gives more detail about the first. The first talks about using outside sources, and the second explains how quoting or summarizing can help.
• Pair 2 (Paragraph 2 → Paragraph 3): This pair connects because the third paragraph adds a contrast. It starts with 'but', showing that while quoting is helpful, sometimes you need to explain a point.
• Pair 3 (Paragraph 3 → Paragraph 4): This pair connects because the fourth paragraph explains how to explain a point. It shows that paraphrasing is a way to provide evidence.
• Pair 4 (Paragraph 4 → Paragraph 5): This pair connects because the fifth paragraph continues the idea of paraphrasing. It shows how paraphrasing can support your own ideas.