I don't know the cause of his abrupt leave.

我不知道他突然离去的原因。

I have some acquaintance with English, but I do not know it well.

我稍懂些英语, 但并不精通。

Don’t ask him to organize things! He doesn’t know his arse from his elbow!

千万别让他来组织，他窍不通。

These rookie cops don’t know anything yet.

这些新警察什么都不懂。

We don't know all the circumstances, so it would be pointless to speculate.

我们不了解所有的情况, 妄加推测是没有意义的。

Her husband doesn’t know it, but she’s got a boyfriend on the side.

她丈夫不知道，她暗地里有个男朋友。

I don't know, he looks kind of hairy and slobbery to me.

我不知道。可我得他看上去毛茸茸的，而口水。

He's very young and inexperienced, and doesn't know about the ways of the world.

他很年轻, 又缺乏经验, 不懂得人情世故。

They did not know that Parvus did everything on a large scale .

其实他们不知道，帕尔乌斯做事向来是大手大脚的。

I don't know why caffeine's suddenly got such a bad rep.

我不知道为什么咖啡因突然得了这么个坏名声。

Lily Geeze, I didn't know those were also swimming events!

天哪，我原来都不知道这些也属于游泳项目呢。

I don't know he was a gay person.

我不知道他是同性恋者。

I don’t know all the ins and outs of the case.

我不知道这个案子的是非曲折。

I didn't know what I was letting myself in for.

我不知道自己会卷入什么样的麻烦之中。

I don’t know why she’s marrying that man. I wouldn’t touch him with a bargepole.

我不明白她为什么要嫁给那个人，我都不想理他。

Maximizers are people who obsess over every decision, who don't know how to satisfice.

贪得无厌的人就是那些对每个决定都患得患失，而从不知足的人。

"I don't know about that," said Halidome, more and more superior as Shelton grew warmer.

“这点我不知道，”哈立桐说，谢尔顿越激动，他就越占上风。

Humanity? You don't know the meaning of the word!.

“人性？你乱扯什么人性！”。

He does not know what nerves are.

他不知道什么叫害怕。

We’re on nodding terms with our neighbours but we don’t know anyone else at all.

我们与邻居是点头之交，不过其他人就不认得了。