primary gun主炮primaryadj.首要的；主要的；初级的；初等教育的；根本的；初期的n.第一位；初选；最主要者；要素；原色；初级线圈primary medullary ray初生髓射线primary relay station第一级转报站primary liquid trough原液槽primary digital group数字基群primary visual center初级视中枢primary circuit route主路由primary electron beam原始电子束Primary Recovery Site主回收地点primary tympanoplasty一期鼓室成形术Primary dysmenorrheal原发性痛经