谁知道

At that time no one knew who she was.

那时候没有一个人知道她是谁。

At this point, no one knows what will happen ...

此时此刻，谁也不知道会发生什么。。。。。。

I didn't know who he was at that moment.

在那个时候我不知道他是谁。

I didn't know who he was at the/that moment.

那个 时候我不知道他是谁。

I wonder who is at the door.

我想知道谁在门口。

A: I wonder who is at the door.

我想知道谁在门口。

While at my worst,I learned my best.

当我迷失的时候，我才知道自己是谁

I know you know who ate the last piece of cake .

我知道你清楚是谁吃的最后一块蛋糕。

But, who is the person that do you know the treatment of component of core of the first atom bomb?

可是，你知道第一颗原子弹核心部件的加工者是谁吗？

I don't know who will attend it.

但我不知道谁会参加。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。