3 H 2 2 3 [B] [A] 3 3 2 [C] 20218/21 Chemistry Departme nt of Fudan UniversityPhysical ChemistryI Chemistry Department of Fudan University Chapter IV Molecular Symmetry and Point Group 2021/8/21 4 [A] [B] [C] C3 1 N H H1 2 H3 N H H3 1 H2 N H H2 3 H1 C3 C3 C 1 3 1