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 what universities must do to attract students from disadvantaged backgrounds. This is a broad overview of the issue. It does not refer to any previous information, so it stands alone. Why other lines are not chosen? Paragraph 2 starts with "Professor Les Ebdon," which is a specific reference and does not stand alone. Paragraph 3 uses "In a statement issued yesterday," which also needs context. Paragraph 4 starts with "Such defenses," which refers back to previous ideas and cannot stand alone.

Concluding sentence: Why this is the last line? This paragraph is the last line because it wraps up the discussion. It summarizes Prof Ebdon's view on the defenses made by universities and calls for action. It brings together the main points made in the earlier paragraphs.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it continues the topic of universities and their responsibilities. It uses a logical order, showing what Prof Ebdon says about the need for universities to change.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 follows Paragraph 2 because it gives more details about what Prof Ebdon said. It uses a logical order, explaining the argument he dismissed.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because it continues to discuss the defenses made by universities. It uses a cause and effect relationship, showing that Prof Ebdon believes these defenses are not valid.