A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first line because it introduces the main idea about Sudan and the Festival of the Nile. It gives a personal feeling about Sudan being the heart of Africa. This is an introductory statement that sets the theme for the following paragraphs. Why other lines are not chosen? Paragraph 2 starts with "The festival" which refers back to the festival mentioned in the first paragraph, so it is not independent. Paragraph 3 starts with "A program" which does not stand alone and needs more context. Paragraph 4 starts with "The British Council" which also refers back to previous information, making it not independent.

Concluding sentence: Why this is the last line? This paragraph is the last line because it wraps up the information about the British Council and its activities. It gives a clear conclusion about what the British Council does, which relates to the festival mentioned earlier. This follows the Summary Style rule, as it brings together the earlier points about the festival and the British Council.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it talks about the festival mentioned in the first paragraph. This shows a logical order where the first paragraph gives a personal feeling about the festival, and the second paragraph explains who organized it. This follows the Logical Order rule.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects to Paragraph 2 because it gives more information about the British Council Sudan. It explains a program that is related to the festival. This shows a Broader to Specific Strategy where the second paragraph gives a specific event and the third paragraph gives more details about the organization behind it.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because it continues to talk about the British Council. It shows what the British Council does, which includes hosting an arts festival. This follows the Topical Order rule, as both paragraphs focus on the British Council.