A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main idea about answering questions based on marks. It sets up the topic without going into details. It does not use any pronouns or definite articles that need prior context. Why other lines are not chosen? Paragraph 2 starts with "Even if" which is a conjunction, so it cannot be independent. Paragraph 3 starts with "And" which is also a conjunction. Paragraph 4 uses "this" which refers back to something not mentioned before, so it is not independent.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the advice given in the previous paragraphs. It gives a final warning about wasting time, which is the main theme of the text.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it continues the idea of managing time based on marks. It gives advice on how to use time wisely when answering questions.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 follows Paragraph 2 because it gives more advice on what to do if you cannot think of an answer. It shows a logical order of steps to take when answering questions.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because it gives a warning about wasting time. It shows the importance of staying focused on the question.