extra fee额外费用extraadj.额外的n.额外之物；临时演员adv.特别地Extra-gradient projection method梯度投影算法extra conductive furnace black ECF超导电炉黑Extracorporal shockwave lithotipsy体外震波碎石Extraperitoneal radical cystectomy腹膜外全膀胱切除Extrahepatic arterial blood supply肝外供血extra-high-density floppy disk超高密度软盘extracurricular volleyball fitness课外排球健身extraoral radiographic examination口外X线照相检查extra-long near-bit stabilizer超长近钻头稳定器extracurricular physical exercises课外体育活动