extra ply附加层extraadj.额外的n.额外之物；临时演员adv.特别地extracelluar proteolysis侧支血管extra low-permeability特低渗透率extra-budgetary source预算外来源Extraembryonic mesoblast胚外中胚层extralinguistic features超语言特征extracellular proteinase胞外蛋白酶Extra - floral nectary花外蜜腺extrafield hallucination域外幻觉extramural training base校外实训基地extra-metamathematicaladj.附加元数学的