每ー個(gè)生物體都以某種覆蓋物，如殼體、皮膚或膜，使其與外界隔離開來。

* Each type of motor has its particular field of usefulness.

每種型號(hào)的發(fā)電機(jī)都有其特定的適用范圍。

* There are three groups of electric motors according to their construction and type of power used: universal, a.c. and d.c.

電動(dòng)機(jī)按照其構(gòu)造和使用的電源可分為三類：通用電動(dòng)機(jī)，交流電動(dòng)機(jī)和直流電動(dòng)機(jī)。

2. 還原

所謂還原就是將形容詞性的物主代詞譯成這個(gè)代詞所代替的名詞，有時(shí)需要増加“該”。如：

* Radio waves are similar to light waves except that their wavelength is much greater.

無線電波與光波相似，但無線電波的波長(zhǎng)要長(zhǎng)得多。

* The greater the number of the free electrons in a material is, the better its conductivity.

材料的自由電子數(shù)量越多，該材料的導(dǎo)電性越好。?

3. 互換

在翻譯英語的偏正復(fù)合結(jié)構(gòu)的句子時(shí)，第三人稱單數(shù)的形容詞性物主代詞常與它所代替的名詞位置互換。如：

* Its being fusible makes metal into liquid when the temperature is high enough.

由于金屬是可熔的，所以當(dāng)溫度相當(dāng)高吋，它就會(huì)成為液體。

* It is possible to differentiate these reactions owing to their difference in intensity.

因?yàn)榉磻?yīng)的強(qiáng)度不同，所以要把它們區(qū)分開來是完全可能的。

4. 轉(zhuǎn)譯為反身代詞

有時(shí)候，形容詞性的物主代詞可以譯成反身代詞“自己”。如：

* People would probably have to take so much Valium to jolt their pacemakers that the cure would be worse than the disease.

為了突然改變自己的整律器，人們很可能需要服用大量安定，只是用藥的結(jié)果比疾病本身更糟。

* Because each gene has its unique sequence of different DNA subunits, the precise sequence can be registered.

因?yàn)槊總€(gè)基因的不同的DNA副族都有自己的獨(dú)特的序列，這一精確的序列可以注冊(cè)。