A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first line because it introduces the main topic of the text, which is about the drop in new home sales. It does not refer to any previous information and sets the stage for the discussion. 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 "House prices also eased," which uses a connector. Paragraph 3 mentions specific numbers without introducing the topic. Paragraph 4 talks about a drop in the west but does not introduce the main topic. Paragraph 5 is a quote and does not stand alone. Paragraph 6 starts with "However," which is a conjunction.

Concluding sentence: Why this is the last line? This paragraph is the last line because it wraps up the discussion by showing the Federal Reserve's view on the situation. It uses conclusive language by indicating concern about unsold homes, which reflects the overarching theme of the text.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it continues the topic of the housing market. The phrase "House prices also eased" shows a logical order of ideas, linking the drop in sales to the decrease in house prices.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 follows Paragraph 2 logically because it provides specific details about the sales pace and inventory. This is a Broader to Specific Strategy, where the general statement about house prices leads to specific sales data.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 by providing specific information about where the biggest drop in sales occurred. This shows a Logical Order as it narrows down the information from general sales data to a specific region.
• Pair 4 (Paragraph 4 → Paragraph 5): Paragraph 5 follows Paragraph 4 because it provides expert commentary on the situation. This is a Topic Example strategy, where the expert's opinion supports the previous information about the drop in sales.