extraboldn.特黑体字adj.用特黑体字排印的extraadj.额外的n.额外之物；临时演员adv.特别地extra-low oxygen steel超低氧钢extracorpored shock wave体外冲击波extratropical transition变性extraterritorial effects域外效力extranuclear interaction核外相互作用Extracorporeal Perfusion体外灌注Extra Linguistic Factors超语言因素extraterestrial disposal地(球)外处置(法); 外层空间处置(法)extra-long road tunnel特长公路隧道extra - radiofrequency体外射频