extra arm外臂, 可变臂extraadj.额外的n.额外之物；临时演员adv.特别地extracorporeal circuIation[医] 体外循环extrapyramidal side effect锥体外系副作用extraterrestrial chemistry地外化学,行星(际)化学extracorporeal irradiation离子辐照extracellular triterpenoid胞外三萜extraretinal photoreceptor视网膜外光感受器extrapleural tboracoplasty[医] 胸膜外胸廓成形术extraembryonic endothelium胚体外内皮extragonadal aromatization性腺外芳香化extraterritorial operation域外施行