Symmsn.西姆斯SYMabbr.符号(=symbol)abbr.对称(=symmetry)symboilc signs marking machine印符号机Symmetic Encryption Technology对称加密技术sym-dichloroacetic anhydride氯乙酸酐symplectic-reality condition辛-实性条件sym-di-O-tolyl guanidine均二邻甲苯基胍sym-dibrometetrafluoroethane四氟二溴乙烷sympathogonioma tenuiflbrillare[医] 原纤维性交感神经原细胞瘤sym-dichloroisopropyl alcohol对称二氯异丙醇sympathogonioma tenuifibrillare原纤维性交感神经元细胞瘤symplectic transformation group辛变换群