* The principle that gas can function while expanding has been applied to the steam engine.

气体在膨胀时能做功，这一原理已应用于蒸汽机上。

2. 译成汉语的定语

尽管同位语从句不是定语从句，但有时其意义上和形式上接近定语从句，故汉译时也常把同位语从句转译为定语。如：

* The possibility that a circuit breaker may fail to perform its function, when instructed to do so, is higher than for protection and trip circuit.

这样做以后，断路器失灵的可能性高于保护和跳闸回路失灵的可能性。

* We all know the fact that all elements are made up of atoms.

我们都知道元素都是由原子组成的这一事实。

* The theory that heat is motion explains simply how supplying heat to a gas causes its pressure to increase.

热就是运动的理论清楚地解释了供给气体热量怎样引起气体的压力增加。 

3. 译成主谓结构短语

有时同位语说明的名词常常含有动作意义，如suggestion，assumption, doubt, hope 等。由于这样的名词在汉译时常常被转译成汉语的动词，故同位语从句往往随之被译为汉语的主谓结构的短语（类似宾语从句）。如：

* The assumption is made that the cylinder is a perfect nonconductor of heat.

假定汽缸是ー种完全的非导热体。