短語詞組短語torsion subgroup [數(shù)]撓子群commutator subgroup 交換子子群;交換子群Subgroup Median 組中位數(shù)proper subgroup [數(shù)]真子群universal subgroup 通用子群characteristic subgroup 特沼群;[數(shù)]特征子群cyclic subgroup 循環(huán)子群calcium subgroup 含鈣水亞組isolated subgroup 孤立子群normal subgroup 正槼子群；不變子群 返回 subgroup