A previously unknown extremist group has said it carried out Friday's bomb attack.

Owen died an unknown provincial.

欧文死的时候是一个不为人知的外乡人。

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？

An unknown number of demonstrators were arrested.

有数目不详的示威者遭到了逮捕。

The motive for the killing is unknown.

杀人动机不明。

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。

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。

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 species of insect previously unknown to science

科学上以前尚未了解的一种昆虫

a hitherto unknown species of moth

迄今仍属未知种类的蛾

The authorship of the poem is unknown.

这首诗的作者不详。

Metals expand when they are heated.

金属受了热就会膨胀.

When he saw the land ahead, the swimmer redoubled his speed.

那个游泳者看见前面有陆地时, 大大地加快了他的速度.

He had gone when I arrived.

当我到达时,他业已走了.

I'm always nervous when I make a speech.

在发言时我总是感到紧张.

Mrs Anne Sterling did not think of the risk she was taking when she ran through a forest after two men.

安妮·斯特林夫人穿越森林追赶那两个男人时,没有去想自己所冒的风险.

When the seas are in turmoil , heroes are on their mettle.

沧海横流,方显出英雄本色.

When I read this article, thoughts thronged my mind and I couldn't sleep.

读了这篇文章后,我浮想联翩,夜不能寐.

We'll give the enemy beans when they come within range.

敌人一旦进入射程,我们就惩罚他们.

When money falls in value, there is no encouragement to save.

货币贬值时, 就无法鼓励人们储蓄.

As the jewel was in the rough state , he had no idea what size it would be when cut.

这块宝石未经琢磨, 他不知道加工后有多大.