extramann.机械手extraadj.额外的n.额外之物；临时演员adv.特别地extralimit issue限外发行Extra dimensions额外维extraprostatitis[医] 前列腺周炎extra investment额外投资extra bottom kit犁梁底extrabranchialis鳃外的Extradural space硬膜外隙extra reflection额外反射extra low carbon超低碳extra feed valve外喂油阀