A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of the text, which is the importance of a happy home for a child. It is a general statement that does not need any other sentence for context. It does not start with a conjunction or use pronouns. 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 'If' which is a conjunction. Paragraph 3 starts with 'It' which is a pronoun. Paragraph 4 starts with 'If' which is also a conjunction. Paragraph 5 starts with 'If' which is again a conjunction.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the discussion by showing the negative side. It explains what can happen if a child does not have a happy home. This gives a clear conclusion to the topic.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects with Paragraph 1 because it explains how a happy home helps a child. The phrase 'Such an environment' refers back to the happy home mentioned in Paragraph 1. This shows a clear logical order.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects with Paragraph 2 because it continues to explain the benefits of a happy home. The phrase 'It also' shows that this is another benefit, linking the ideas together.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects with Paragraph 3 because it talks about the results of having a happy home. The good judgement mentioned in Paragraph 4 is a result of the support from a happy home, showing a logical order.
• Pair 4 (Paragraph 4 → Paragraph 5): Paragraph 5 connects with Paragraph 4 because it presents a contrast. It shows what can happen if a child does not have a good home. The use of 'If he fails' introduces a different outcome, linking the two ideas.