需要时

00 For Introduction to Electrodynamics by Griffiths Prentice-Hall, 1989

需要指出的是，上面的价格是文章写作时（1998年2月）从Amazon网上书店查到的价格。

The results showed that,in actual operation,the device should be optimized based on the comprehensive consideration on the influence of electrolyzer voltage on every operation p...

结果表明，在实际运行中需要综合槽压对各种操作参数的影响而对其进行优化，槽压在3.5～4.0 V时，运行效果最佳。该实验为膜电解钠碱法脱硫的应用提供了依据。

Without going into a great deal of theory regarding electrochemical principles and the solution of metals, it has been determined that corrosion of steel is stopped when its potential to a copper-copper sulfate electrode is –0.5 volt or more electronegative with the reference electrode placed close to the electrolyte/structure interface.

不需要太多的电化学原理和金属溶液理论，人们已经知道，当把参比电极放于电解质和结构界面附近，钢或铁相对于铜－硫酸铜电极的电位达到－0.5伏或更负时，钢、铁的腐蚀就会停止。

Elementary transformation, matrix inversion using a written calculation method...

初等变换法，矩阵求逆用的是笔算时惯用的方法，需要高斯消去法的朋友请参看有关资料。

Get there by the Docklands Light Railway, with elevated tracks giving wonderful views into a world of glass and steel.

入住时需要出示身份证和信用卡或者交付保证金，以便于支付其他杂项的费用。

He is such an elusive person; you never know where he is when you want him.

他就是这样一个难以捉摸的人；当你需要他时永远不知道他在哪里。

It was a superb defensive unit, but in offensive operations it required substantial support to get to a forward emplacement.

他是最佳的防御单位，但在攻击行动时需要独立火力支援来向前推进并展开炮座。

Not know what empress beginning I am already the academic association depend on you, Is to need you.

不知什么时后开始我已学会依赖你，我需要你。

When the emulation result of the model is not satisfied, it need the result to be controled.

当模型的的仿真结果不令满意时，就需要对结果进行控制。

The design of the endoskeleton could be the most powerful "assist" in movie history—Schwarzenegger barely needed to do anything, as the Terminator was firmly in our minds already.

这个机器骨架的制造可以说弥补了电影史上的不足---当终结者的形象已经深深地刻在我们的心中时，Schwarzenegger基本上不需要做什么额外的工作了。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。