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 vision and echolocation together. This is a general statement that does not need other sentences for context. It does not use any pronouns or definite articles that refer to previous ideas. Why other lines are not chosen? The other paragraphs are not chosen because they do not meet the criteria for being independent. For example, Paragraph 2 starts with 'One narrow range...' which is not a general statement. Paragraph 3 starts with 'Why, then...' which is a question and needs context. Paragraph 4 starts with 'Because...' which shows a reason and needs a previous statement. Paragraph 5 starts with 'Echolocation is...' which refers back to the topic and is not independent.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it gives a specific example that wraps up the discussion. It explains when echolocation is useful, which relates back to the main topic. This is a Summary Style because it brings together the earlier points about vision and echolocation.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects with Paragraph 1 because it gives more detail about the features of vision and echolocation. This is a Broader to Specific Strategy. The first sentence is general, and the second sentence explains it further.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects with Paragraph 2 because it asks a question about the information given in the second paragraph. This is a Question→Answer Structure. The second paragraph gives facts, and the third paragraph asks why these facts are important.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects with Paragraph 3 because it answers the question asked in the third paragraph. This is a Question→Answer Structure. The third paragraph asks why vision is common, and the fourth paragraph gives the reason.
• Pair 4 (Paragraph 4 → Paragraph 5): Paragraph 5 connects with Paragraph 4 because it gives an example of when echolocation is used. This is a Topic Example Strategy. The fourth paragraph states that vision is better, and the fifth paragraph explains when echolocation is needed.