A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first line because it introduces the main topic. It talks about how journalists find it hard to be objective. This is a general statement that sets the stage for the rest of the text. It does not refer to any previous information. Why other lines are not chosen? Paragraph 2 starts with 'Journalists' which is a pronoun and refers back to the journalists in Paragraph 1. Paragraph 3 starts with 'However', which is a conjunction and shows a continuation of thought. Paragraph 4 starts with 'Some aspects', which uses a determiner that refers to information not yet introduced.

Concluding sentence: Why this is the last line? This paragraph is the last line because it summarizes the main point. It shows the outcome of the discussion about journalists and their reporting. It wraps up the ideas presented in the previous paragraphs.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects with Paragraph 1 because it continues the idea of journalists. It shows what journalists do to try to be objective. This is a logical order of thought.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects with Paragraph 2 because it uses 'However' to show a contrast. It talks about the difficulty of including every aspect, which relates to the effort of journalists in Paragraph 2.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects with Paragraph 3 because it explains the result of not including every aspect. It shows that some aspects are missing in reporting, which follows the idea from Paragraph 3.