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. It gives a broad overview of the region and sets the stage for what follows. It does not refer to any previous information, making it independent. Why other lines are not chosen? Paragraph 2 starts with "Much of it..." which uses the definite article "it" and refers back to something not yet introduced. Paragraph 3 starts with "There is very little..." which also uses a pronoun and does not stand alone. Paragraph 4 starts with "The locals..." which uses a definite article and assumes prior knowledge. Paragraph 5 starts with "It covers..." which again uses a pronoun and does not stand alone.

Concluding sentence: Why this is the last line? This paragraph is the last line because it wraps up the discussion about the desert. It gives a final detail about the geography and travel in the area, summarizing the main points made in the text.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects with Paragraph 1 because it continues the topic of the region. The phrase "Much of it" refers back to the region mentioned in Paragraph 1, showing a logical order.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects with Paragraph 2 because it gives more details about the Taklimakan desert. It explains why it is hostile, showing a broader to specific strategy.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects with Paragraph 3 because it talks about the locals' views on the desert. It shows a cause and effect relationship where the harsh conditions lead to the locals' respect for the land.
• Pair 4 (Paragraph 4 → Paragraph 5): Paragraph 5 connects with Paragraph 4 because it describes the geography of the area. It continues the theme of the desert and shows how it affects travel, following a logical order.