externalityn.外表；外在性；外部的事物；外部因素externaladj.外来的；外部的；外面的；表面的n.外观；外部；外界事物externally prestressed体外预应力external bricking-up外墙砌体external taper turning外锥度车削external living beings外来生物external void fraction外部空隙分率external spiral groove外螺旋沟external basic lamella外环骨板external ethmoidectomy鼻外筛窦切除术external open juncture外部开音渡external spiral bundle外螺旋神经束