The whereabouts of this man is unknown .
这个人去向 不明。
The date of birth and death of Qu Yuan is unknown .
屈原的生卒年月 不详。
He was an unknown writer .
他是个 名不见经传的作家。
His present whereabouts is unknown . ; His whereabouts is uncertain .
他目前下落 不明。
He is an unknown quantity for his rivals .
对于对手们而言，他是个 未知数。
This truck is of unknown origin .
这辆卡车 来历不明。
Ignorance of people brings fear fear of the unknown .
人们的无知会带来恐惧，对 未知 事物的恐惧。
The contract was awarded to a previously unknown company
合同签给了一个之前 并不 知名的公司。
How did you expect us to proceed on such a perilous expedition through unknown terrain
你怎么能指望我们如此冒险地穿越 未知的地域，继续这一探险？
The timing of the attack and its motivations are unknown .
袭击发生的时间及其动机 尚 不 清楚。
The details of the case is unknown .
案情 未详。
Unknown thieves had forced their way into the apartment
不 知名的窃贼破门闯入了公寓。
Unknown attackers riddled two homes with gunfire
来路 不明的袭击者用枪炮将两处住宅打得千疮百孔。
Exactly which bacteria cause the infection is still unknown .
到底是什么细菌引起的感染还 不 清楚。
The motive for the killing is unknown .
杀人动机 不明。
There towers aloft in the square the Monument of Unknown Heroes .
广场上矗立着 无名英雄纪念碑。
His present whereabouts is unknown .
他去处 不明。
A hundred years ago coronary heart disease was virtually unknown in Europe and America .
在100年前冠心病几乎 不存在于欧洲和美洲。
The whereabouts of the missing child is still unknown .
遗失的孩子还 没有着落。
It is not unknown for valuable display items to go ahem missing .
贵重的展品，呃哼，丢失的话，会众人 皆知。
You must eliminate an unknown quantity .
你必须消去一个 未知数。
I could not understand how someone with so many awards could be unknown to me .
我想 不通自己竟然不认识获了这么多奖的人。
A previously unknown extremist group has said it carried out Friday 's bomb attack .
一个先前 不为人知的极端组织声称实施了星期五的炸弹袭击。
Once more he 's making a leap into the unknown without a plan .
他再次毫无计划地乱 闯。
The condition is practically unknown outside psychiatry clinics .
除了医院的精神病科外，这种病几乎 不为人知。
The address is unknown to me .
地址 未详。
An unknown number of demonstrators were arrested
有数目 不详的示威者遭到了逮捕。
His whereabouts have been utterly unknown so far .
迄今他的下落全然 未知。
My husband for some unknown reason suggested that I loved my birds more than him : as if I would
我丈夫， 莫名其妙地，暗示我爱鸟甚于爱他：仿佛我真如此似的。
The letter had come from an unknown mischief-maker .
这封信来自一个 匿名的离间者。
美[ˌʌnˈnoʊn]英[ˌʌnˈnəʊn]
adj.未知的不出名的从未发生的从不存在的
n.未知数不知名或不出名的人未知的事物<数>未知数