何时

Identification of the first magnetic tape, drum, and disk systems is difficult.

考证第一部磁带，磁鼓或磁盘系统究竟是何时制成的，这是一件颇不容易的事。

But understanding how the magnetosphere works now should help to deal with the consequences if and when it vanishes .

但是，不论地球磁场是否消失或何时消失，深刻地理解磁气圈的工作原理都会有助于人们去解决磁场消失后所出现的一切。

Extension of the main clause and tells us when, why, for what purposes, and underwhat conditions the event in the main clause happens.

子句便是主干子句的伸延和告诉我们主干子句内的事情在何时，为什麼，有什麼目的，和在什麼状况

For a man-powered light as bright as this one, it doesn't require recognizable extra energy to power it, and it releases a rider of the worries about when to recharge or to change batteries, in addition it has a working life of 100 thousand hours and needs no amount of maintenance, it's quite worthy to have it.

像这种人力发电的头灯，踩亮所需的额外体力几乎察觉不到，也免除了何时需要充电或更换电池的担忧，其使用寿命达10万小时，不需要任何维护，的确值得拥有。

When we see a mannequin, we think of fashion design.

无论在何时何地，只要看到它，就一定会联想到服装设计。

I had to know at all times who was going to be there and anticipate what Marjorie would need next, so it was always on my mind," says Henrich."It was something I wanted to do, but it also never went away.

我不得不无时无刻弄清楚，何时会是谁在那里，并预计接下来马乔里将会需要什么，"亨利希说，"这本来就是我想做的事，但一旦做了，就不能放手了。

The transition of debts and assets are modelledby a Markov chain according to the structure of the bank system.

在银行结构给定的情况下，采用Markov链来分析银行之间债务的转移以及何时破产等问题。

Can you tell us when and where he received the Master's Degree?

你可以告诉我们他是在何时何地获得硕士学位的吗？

"You can see where lava has flown into wet sand and then next to it where it's flown over dry land, and that gives us an indication of when different things were happening millions of years ago," Mateus explained.

马泰乌斯解释说：「你可以看见火山喷发的熔岩流入潮湿的沙地，再流到邻近乾燥的沙地上，这可以提示我们，千百万年前不同的事何时发生。

Matin newspaper report that Jolie gave birth to a boy, Knox Leon, and a girl, Vivienne Marcheline, by Cesarean section on Saturday night.

不知道从何时起，我成了Jolie的粉丝。特别爱看她和她的孩子们在一起的照片。那超乎寻常的四个小联合国军

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。