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 gives a clear definition of what a pilgrimage is. This follows the rule of Topic Sentence, as it sets up the main idea without going into details. Why other lines are not choosen? The other paragraphs are not chosen because they do not stand alone as the first sentence. For example, 'The person who makes this journey...' starts with a pronoun and needs context. 'For hundreds of years...' refers to past actions and needs a subject. 'People go on these pilgrimages...' is too specific and assumes knowledge of what a pilgrimage is.

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 summarizes the reasons for the pilgrimages, which is the final thought of the discussion.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it explains who takes part in a pilgrimage. This follows the Broader to Specific Strategy, as it gives more detail about the topic introduced in Paragraph 1.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects to Paragraph 2 because it gives examples of pilgrims. This follows the Logical Order rule, as it continues the idea of who pilgrims are and what they do.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because it explains why people go on these journeys. This follows the Cause and Effect Relationship rule, as it shows the reasons behind the actions of the pilgrims.