Metals differ in the ease with which they give up electrons and enter into chemical combination. Internal-shoe drum brakes provide better protection from water and dust.

People on earth are protected from the dangerous ultraviolet radiation of the sun by a layer or ozone that spans the planet and absorbs the radiation.

各种金属放出电子和参与化学反应的难易程度不一。

内蹄式鼓形制动器的防水、防尘性能比较好。

地球上的人们受到包围着地球并能吸收辐射的一层臭氧层的保护，从而免受危险的太阳紫外线辐射的伤害。

According to the molecular theory the temperature of an object depends on the average speed of its molecules.

Effectiveness of temperature control depends upon the amount of lubricant supplied, the ambient temperature, and the external cooling.

根据分子理论的原理，物体的温度取决于其分子的平均速度。

温度控制的效果取决于润滑剂的用量、环境温度以及外部的冷却设施。

第1节 翻译练习3

Particular attention should be given to hoses to ensure that chafing does not occur.

The primary concern of electrical engineering is the doing of work by the delivery of energy. Gene piracy is not new.

All plants and animals need carbon for growth.

要特别注意软管，保证没有擦伤。

窃取基因不是新鲜事。

电工学主要关注的是通过输送能量做功的情况。

所有动植物均需要碳才能生长。

第1节 翻译练习4

The experiment was a success.

Semiconductor devices can perform a variety of control function in electronic equipment. 这个试验是成功的。

半导体在电子设备中能起各种各样的控制作用。

3.2 冠词的译法

第2节 翻译练习1

A polymer is a substance of high molecular weight.

Being a good insulator, rubber is often used in cables.

The patient was administered the mixture twice a week.

These machines may be oiled once or twice a month.

聚合物是一种高分子的物质。

这种混合剂病人每周服用两次。

橡胶是一种良好的绝缘体，所以经常使用在电缆上。

这些机器每个月可以加一次或两次油。

第2节 翻译练习2

A bearing can be defined as a member specifically designed to support moving machine components.

Use a transformer and power at low voltage can be changed into power at high voltage.

An object at rest has no kinetic energy, its velocity being zero.

轴承可以定义为一种专门用于支撑运动着的机器零件的构件。