extrahead反常带头extraadj.额外的n.额外之物；临时演员adv.特别地extrathyroid thyroxine甲状腺外甲状腺素extracellular fraction胞外组分extra code instruction附加码指令extracavity modulation腔外调制extra capsular forceps晶体囊外镊extracellular protease胞外蛋白酶Extrahepatic blie duct肝外胆管extrapolation distance外推距离Extradural anaesthesia硬膜外麻醉extraluminal leiomyoma[宫]腔外性平滑肌瘤