骨干

activists;backbone activists;core (or key)member;mainstay
领导～ mainstay of the leadership;core leadership;key leaders/坚决的～分子backbone die-hard elements/右翼～ nucleus of the right wing/～队伍backbone contingent;backbone/～企业key (or backbone)enterprise/～项目key project/～作用act as the mainstay;play a major role