Change of Exercises in Senior High School Chemistry Textbooks Since Reform and Opening Up: Sulfur and Nitrogen Elements and Their Compounds
YAO Juan-Juan1,2**, WANG Hou-Xiong1, LI Meng3
1. Department of Artificial Intelligence Education, Central China Normal University, Wuhan 430079, China; 2. College of Chemical and Pharmaceutical Engineering, Hefei Normal University, Hefei 230601, China; 3. College of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China
