A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of South Sudan's poverty. It gives a broad overview of the situation without needing prior 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: 1) "Nearly eight out of 10 people live in poverty" starts with a specific statistic and does not introduce the topic. 2) "The country is a classic case of 'compounding' crisis" uses the definite article 'the' which assumes prior knowledge. 3) "These have increased food insecurity" uses the pronoun 'these' which refers back to previous ideas.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it summarizes the effects of the crises discussed in the previous paragraphs. It brings together the main points about poverty and food insecurity in South Sudan.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it gives a specific detail about the poverty in South Sudan. This follows the Broader to Specific Strategy, where the first paragraph gives a general idea and the second gives a specific fact.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects to Paragraph 2 because it explains the situation in South Sudan further. It shows the cause of the poverty mentioned in Paragraph 2. This follows the Cause and Effect Relationship rule.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because it explains the effects of the crises mentioned in Paragraph 3. This follows the Cause and Effect Relationship rule, showing how the crises lead to food insecurity.