The details of the principal cause are not known.

主因未详.

《现代汉英综合大词典》

The thing was not known to be litigious when purchased.

那东西买来时大家都不知道它在法律上是有问题的.

《现代英汉综合大词典》

In a word, you found out something you had not known before.

一句话, 你弄懂你以前不明白的事.

英语晨读30分（高一）

The function of the albumen cells is not known.

白蛋白细胞的功能尚不清楚.

辞典例句

It was a dark enriching influence she had not known before.

这是一种她从来未感受到的朦胧而又不断丰美的感化力量.

辞典例句

Those who have not known hunger can never imagine how it feels.

没挨过饿的人不知道饥饿是什么滋味.

辞典例句

Just how Fermat's ideas on coordinate geomitry evolved is not known.

Fermat的坐标几何究竟是怎样产生的,我们尚不知道.

辞典例句

Further, all the laws of nature that govern the particle motion are not known.

再者, 支配粒子运动的一切自然规律也都是未知的.

辞典例句

Whether he had died or still lingered in the dungeons of Austria was not known.

他究竟是已离人世,还是仍被关在奥地利的地牢里,谁也不知道.

辞典例句

How could I have not known that he was bribing this woman from the city council?

我怎么会不知道他向这个女市议员贿赂?

电影对白

Since April, we had not known any peace, only war and suffering.

从四月开始, 我们就在感受不到任何的和平, 只感受到战争和苦难.

互联网

It is not known who the alleged buyers of the technology were.

目前尚不清楚是谁涉嫌购买了这些技术.

互联网

The exact relationship between BH growth and bulge formation is not known.

黑洞成长和椭圆星系形成之间确切的关系目前并不明确.

互联网

Returns the uncompressed size of the entry data, or - 1 if not known.

返回未压缩的项数据大小,如果未知, 返回 -1.

互联网

But production of precision ceramic pottery -- all, are not known.

但对于生产精陶瓷 -- 紫砂陶毕竟是陌生的.

互联网