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. It talks about the demand for employees and how they are working hard. This is a general statement that sets the stage for the rest of the paragraphs. It does not refer to any previous information. Why other lines are not chosen? The other paragraphs are not chosen because they do not stand alone. For example, Paragraph 2 starts with 'They go to work,' which needs context. Paragraph 3 starts with 'And they went home,' which also needs context. Paragraph 4 talks about managers but does not introduce the topic. Paragraph 5 talks about what managers should do but needs the earlier information to make sense.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the ideas presented in the text. It gives a clear conclusion about what managers should do based on the earlier points. It summarizes the main message of the text.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects with Paragraph 1 because it continues the idea of employees working hard. The phrase 'They go to work very early' shows how employees are responding to the demand mentioned in Paragraph 1. This is a logical order.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects with Paragraph 2 because it shows the result of going to work early. The phrase 'And they went home very late' explains what happens after they start work early. This shows a clear flow of ideas.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects with Paragraph 3 because it talks about the effect of employees overworking. The performance of employees is linked to their long hours, showing a cause and effect relationship.
• Pair 4 (Paragraph 4 → Paragraph 5): Paragraph 5 connects with Paragraph 4 because it gives advice based on the findings in Paragraph 4. The managers' discovery leads to the conclusion that they should take action, showing a logical order.