A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of time in Singapore. It gives a broad overview of Singapore Standard Time without going into details. It does not use any pronouns or definite articles that would need prior context. Why other lines are not chosen? Paragraph 2 starts with 'Singapore initially adopted...' which uses a specific reference and is not independent. Paragraph 3 starts with 'Malaya adopted...' which also refers to a specific event. Paragraph 4 starts with 'While official appointments...' which indicates a continuation of thought. Paragraph 5 starts with 'At the end of the Second World War...' which refers to a specific time and context.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the discussion about time in Singapore. It summarizes the changes that happened after the war and concludes the topic.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it continues the topic of time in Singapore. It shows a broader to specific strategy, moving from the general idea of Singapore Standard Time to the specific time adopted when Singapore was part of British Malaya.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects to Paragraph 2 because it continues the historical timeline of time changes in Malaya. It follows a chronological order, showing what happened after Singapore adopted the Malayan time.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because it explains the practice during the time when Tokyo time was used. It uses the logical order strategy, showing how the practice of keeping two times was related to the adoption of Tokyo time.
• Pair 4 (Paragraph 4 → Paragraph 5): Paragraph 5 connects to Paragraph 4 because it shows the result of the time practices after the war. It follows a cause and effect relationship, explaining what happened at the end of the Second World War.