1、 We bought a drawing by an unknown artist、我们买了一幅某个不出名的画家所作的画。
2、 An unknown disease suddenly attacked the crops in this area、一种尚未搞清的病虫害突然侵袭了这一带的庄稼。
3、 The author had been an unknown until he published his recent book、这位作家一直是个默默无闻的人，直到最近出版了他的一本书。
4、 It was unknown country to me、这地区对我说来是陌生的。