unknowns未知事件unknownadj.未知的；不出名的unknown growth factor未知生长因素unknown to an outsider局外人不得而知unknown network attack未知攻击unknown word detection新词发现unknown input observer未知输入观测器Unknown foreign powder不明异物unknown primary tumors明原发灶Unknown physical agent不明物理因素unknown scale substance不明结垢物unknown elected nominee冷门当选者,黑马