Scientific abstracts can be classified into differ...

Scientific abstracts can be classified into different types according to their purposes and structures. Read the following features of scientific abstracts and group them into proper types. You can add more features to the list. A. Briefly summarizes the background, methods, results and conclusions of the full-length paper. B. Informs the audience of all essential points of the paper. C. Usually very short, about 50─100 words. D. Contains one paragraph with no explicit subheadings. E. Most likely used for sciences, engineering or psychology reports. F. If it is a research paper, includes the background of the paper, sometimes the methods, but never the results or conclusions. G. Contains several paragraphs with explicit subheadings. H. Most likely used for humanities and social science papers or psychology essays. I. Concise, usually 10% of the length of the entire paper, often just one paragraph. J. Most likely used for medical science papers. K. ... L. ... Structured Abstracts include: (输入对应的大写字母，按字母顺序，且字母中间没有标点符号或空格，如：ABCE)