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middle school chemistry information network, the best chemistry discipline network. compilation of the essential high school chemistry and junior high school chemistry data from all over the country. a series of lesson preparation materials, review and test at the end of the chapter, special topic summary and training, stage exams, mock exams, college entrance examinations, competitions, college entrance examinations, and chemistry test questions, chemistry courseware, chemistry lesson plans and other high school chemistry and junior high school chemistry materials.
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