Read the following excerpts (1-5) taken from research papers. Recognize each excerpt’s most distinctive organizational pattern or structure from the choices (A-F) in the box below (each pattern can be used only once).

1. Excerpt 1: Organizational pattern: problem-solution structure. The paragraph presents the problem of efficient removal of As(Illy) from water due to its toxicity, followed by a solution that is the development of a FeM binary oxide material using a simultaneous oxidation and coprecipitation method.
2. Excerpt 2: Organizational pattern: Cause-and-effect structure. The excerpt discusses the causes for clean energy development, which are environmental problems from global warming and uncertain security of conventional energy, along with the effects of establishing a strategic framework for clean energy development, such as maximizing energy security, ecological safety, and sustainable economic and social development.
3. Excerpt 3: Organizational pattern: Chronological structure. The paragraph presents events and developments in the chronological order they occurred, starting with the fireproof construction design by NAME_1 in 1796, electrification by NAME_2 in the early 1830s, and leading up to the development of tall steel skyscrapers in Chicago around 1890.
4. Excerpt 4: Organizational pattern: Comparative structure. The paragraph presents a comparison between A. canescens species and other Atriplex species in terms of salinity tolerance, highlighting A. canescens as a typical h Write exactly 3 paragraphs each separated with two new lines answering this question. The last paragraph must start with "identity".
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