有序商群 2) sequence of quotient groups 商群序列 3) finite quotient 有限商群 1. A polycyclic group G must be 4-generated if all abelian subgroups of eachfinite quotientof G are 3-generated. 设G是个多重循环群 ,若G的每个有限商群的Abel子群都是 3 -生成的 ,则G是 4元生成的 。