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 vascular hemolysis血管外溶血extra-nuclear particle核外粒子extrahepatic cholestasis肝外梗阻Extracranial meningiomas颅外脑膜瘤extra weather resistance超耐候extra adulterating agent外掺剂extra-refractive index[电] 非常拆射率extra-low carbon steel极低碳素钢extramaxillary anchorage颌外安抗extrahepatic cholangioma肝外胆管瘤