81.Television makes it possible for us to see a distant scene as a transmitter at the television stadio telecasts the scene to our receiver.
当电视台的发射机把场景播送到我们的接收机时，电视就使我们能看到远处的场景。(it，是形式宾语，真正的宾语是for us to see a distant scene.)
82.This failure of an object to regain its original size and shape as soon as the deforming force is removed is called elastic lag.
一旦形变力除去之后，物体不能恢复原来的大小和形状，这种现象称为弹性滞后。(fail-ure是名词，在句中作主语。不定式短语to regain.……shape作failure定语。)
83.The purpose of this book is to introduce to the students solutions of problems having close connection with application in industry.
本书的目的是向学生介绍一些习题的解法，这些习题与工业中的应用有着密切的关系。
(不定式短语to introduce.……industry是系词is的表语，用来揭示purpose的内容。)
84.It is clear that insulating materials should have such a high specific resistance as to be，to all intents and purposes，nonconductors of electricity.
显然，绝缘材料具有很高的电阻率，因而实际上是不导电的。 (that引出主语从句，it是形式主语。such.……as to be non-conductor.……表示结果。to all intents and purposes，“实际上”，“事实上”。)
85.The most probable explanation of radioactive disintegration is to be found in terms of the modern ideas concerning the structure of matter.
必须根据物质结构的现代观点才能更好地阐明放射性裂变现象。(is to be found是复合谓语结构，有“应该”，“必须”的含义。in terms of，“根据”。concerning.……是介词短语，修饰ideas.)
86.In solids the molecules are relatively close to each other and the forces of attraction are great enough to hold the molecules in a regular pattern and thus maintain a definite volume and shape.
在固体中，分子彼此结合得很紧密，分子引力大得足以使分子保持在有规则的结构中，从而使固体能维持一定的体积和形状。 (to hold.……and.……maintain.……是不定式短语，起结果状语作用，说明enough.)
87.it is impossible for a sdf-acting machine，unaided by any external agency，to convey heat from one body to another at a higher temperature.
不借助于任何外在因素，自动机不可能把热能从一个物体传递给另一个温度较高的物体。
(不定式短语to convey.……temperature在句中作主语，it是形式主语，for.……machine是不定式toconvey的逻辑主体。分词短语unaided.……agency起状语作用，有条件的意味。)
88.The sun can be said to be the source of nearly all energy， and in the absence of the sun‘sheat and light， no life could exis to nearth.
可以说太阳是几乎所有能量的来源，因此，如果没有太阳的光和热，地球上就不可能有生命。(tobethe.……energy作sun的补足语。)
89.To appreciate the capabilities and limitations of radar，and so to be able to use it to full ad—vantage，it is necessary to understand the character and behaviour of radio waves and to appreciate the principles of their generation and reception，including the presentation of echo to the observer为了正确了解雷达的能力和局限性以便能充分地利用它，就有必要了解无线电波的特性和作用，而且要了解它的产生和接收的一些原理，包括对观察者所产生的回波。 (Toappreci-ate.……radar和so to be able.……advantage都是目的状语。to understand.……waves和to appreciate.……observer都是主语，it为形式主语，代替这两个不定式短语。现在分词短语including为伴随状语，用来对上句谓语表示的行为进行补充说明。to full advantage，“充分地”。)
（责任编辑:doublejp）
