A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first line because it introduces the main topic of the text. It gives a clear definition of electronic skin (e-skin) and explains what it is. This follows the rule of Topic Sentence. Why other lines are not choosen? The other paragraphs are not chosen because they do not stand alone as the first sentence. For example, Paragraph 2 starts with 'A better-known', which is not independent. Paragraph 3 starts with 'Their aim', which uses a pronoun. Paragraph 4 starts with 'Developers', which does not introduce the topic. Paragraph 5 starts with 'More advanced', which is not general enough.

Concluding sentence: Why this is the last line? This paragraph is the last line because it wraps up the main ideas of the text. It gives a clear conclusion about what the developers want to do with e-skins. This follows the rule of Summary Style.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects with Paragraph 1 because it uses the Connector strategy. It mentions another type of electronic wearable, which is an activity tracker. This shows a logical order of ideas.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects with Paragraph 2 because it continues the topic of wearables. It uses the Broader to Specific Strategy. The second paragraph talks about activity trackers, and the third paragraph talks about more advanced wearables.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects with Paragraph 3 because it introduces developers who are working on e-skins. This follows the Logical Order strategy, as it shows the next step in the discussion about wearables.
• Pair 4 (Paragraph 4 → Paragraph 5): Paragraph 5 connects with Paragraph 4 because it explains the aim of the developers mentioned in the previous paragraph. This follows the Topic Example strategy, as it gives an example of what the developers want to achieve.