* Quantities which have both magnitude and direction are called vector quantities.

具有大小和方向的量称为矢量。

* The turret lathe is equipped with a turret for mounting a number of different cutting tools which are used in sequence,

六角车床有ー个六角刀架，用来安装若干把按顺序使用的不同的刀具。

介词+which的定语从句大部分为限制性定语从句，翻译时可将定语从句与主句合译，也可将从句译为“的”字结构。如：

* That's the reason for which the expansion of liquid takes place on the surface only.

那就是为什么液体膨胀只发生在表面的原因。

* Heat is a form of energy into which all other forms are convertible.

热是其他种类的能都可以转换成的一种能。

* No method is known by which it is possible to create energy out of nothing. 

能够凭空创造能量的方法是没有的。

(2) 译为并列分句，这时which可以译为它所代替的先行词，或译为“该”,“它”“这（些）”等。如：

* Laser light is coherent, which means that the outer edges of the beam are almost perfectly parallel to each other.

激光的光是相干的，也就是说，光束的外边沿几乎完全相互平行。

* 1 is the value of constant K, which does not change with any factors.

1是常数K的数值，它不随任何因素的变化而变化。