A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of Greenland. It uses the rule of Topic Sentence because it gives a clear idea about what the text will discuss. It does not need any other sentence for context. Why other lines are not chosen? The other paragraphs are not chosen because they do not stand alone. For example, Paragraph 2 starts with "Most of it" which uses a pronoun that refers back to Greenland. Paragraph 3 starts with "The Norse Vikings" which is specific and needs context. Paragraph 4 starts with "Eric the Red" which also needs prior information.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the information about Greenland's history. It uses the rule of Summary Style because it gives a specific event that relates to the earlier points about Greenland.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects with Paragraph 1 because it gives more details about Greenland. This follows the Broader to Specific Strategy. The first sentence is general, and the second sentence explains more about Greenland's ice.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects with Paragraph 2 because it talks about the discovery of Greenland. This follows the Logical Order rule. The second paragraph describes Greenland's ice, and the third paragraph explains who discovered it.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects with Paragraph 3 because it gives a specific example of a person related to Greenland's history. This follows the Topic Example rule. The third paragraph talks about the Vikings, and the fourth paragraph gives an example of Eric the Red.