A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic. It tells us about the Burj Dubai, which is a tall structure. This is a general statement and does not need other sentences for context. It does not use any pronouns or definite articles that refer to previous information. Why other lines are not chosen? The other paragraphs are not chosen because they do not meet the criteria for being independent. For example: - Paragraph 2 starts with "Standing at" which is not independent. - Paragraph 3 starts with "Note the use" which is also not independent. - Paragraph 4 starts with "A hotel" which could be independent, but it refers back to the building. - Paragraph 5 starts with "Above that" which needs context from previous sentences.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the information about the Burj Dubai. It gives the final details about what is above the hotel. This shows the overall theme of the building's structure.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects with Paragraph 1 because it continues the topic of the Burj Dubai. It gives more details about the height and floors of the building. This shows a logical order of ideas.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects with Paragraph 2 because it talks about the height mentioned in Paragraph 2. It explains why the height is called "estimated". This shows a cause and effect relationship.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects with Paragraph 3 because it shifts the focus from the height to what is inside the building. It gives more information about the hotel, which is part of the Burj Dubai.
• Pair 4 (Paragraph 4 → Paragraph 5): Paragraph 5 connects with Paragraph 4 because it continues to describe what is in the building. It talks about the apartments and offices above the hotel. This shows a logical order of details.