西电科技英语课件——第四章 动词非谓语形式

西安电子科技大学第四章动词非谓语形式主讲: 王琳讲师2006 年7 月14日§4 .1 动词不定式1、普通不定式：其功能有“主、宾、表、定、状、补”（1）主语特点：ⅰ、句子谓语必定为单数第三人称形式ⅱ、往往可用形式主语“it”的句型§4 .1 动词不定式～1、普通不定式（1）主语①“It+ 系动词+ 表语+ 不定式”It is of great interest to study the three laws of motion.It proves convenient to describe the ability to conduct current in terms of conductance（电导）.§4 .1 动词不定式～1、普通不定式（1）主语It is possible to (do …)It is necessary to (do …)It is a simple matter to (do …)“我们能够……”“我们必须……”“……是容易的”①“It + 系动词+ 表语+ 不定式”§4 .1 动词不定式～1、普通不定式（1）主语②“It+ 及物动词（take★, require, do, make）+ 宾语+ 不定式”It takes sunlight about 8minutes to reach the earth.磁化（magnetize）这些物质需要一个强磁场。

§4 .1 动词不定式～1、普通不定式（1）主语It requires a strong magnetic field to magnetize these substances.②“It + 及物动词（take ★, require, do, make ）+ 宾语+ 不定式”§4 .1 动词不定式～1、普通不定式（1）主语②“It+ 及物动词（take★, require, do, make）+ 宾语+ 不定式”解这个方程花了我们两个小时。

§4 .1 动词不定式～1、普通不定式（1）主语②“It+ 及物动词（take★, require, do, make）+ 宾语+ 不定式”It took us two hours to solve this equation.§4 .1 动词不定式～1、普通不定式（1）主语③“It+ 不及物动词（suffice, work, help, occur）+ 不定式”（不常见）It suffices to give one example here.§4 .1 动词不定式～1、普通不定式（1）主语④“It+ 被动语态（desire, leave, find, propose）[ + 主补等] + 不定式”It is desired to solve the equation for the unknown（未知量）.It is left as a problem to show that these equations reduce to（简化成）Eq. (2–7)when the point lies on the x-axis.§4 .1 动词不定式～1、普通不定式（2）宾语：注意以下两点。

①不定式的被动形式作宾语的情况These problems deserve to be further studied.[= It is worth studying these problems further.]§4 .1 动词不定式～1、普通不定式（2）宾语：注意以下两点。

②一个用形式宾语“it”的常用句型“主→谓→it→宾补→不定式”We find it very difficult to solve this problem.We consider it necessary to make measurements with accuracy.§4 .1 动词不定式～1、普通不定式特点：（3）表语ⅰ、主表概念相等ⅱ、只能是主动形式的不定式ⅲ、一般只能用“is ”，且可译成“是”★[否则是一种将来时形式，译成“将；要；应该；会”]§4 .1 动词不定式～1、普通不定式（3）表语The function of an antenna（天线）is to transmit or receive radio waves.*** We are to discuss this point in the next chapter.*** This component（元件）is to be chosen so that the transistor operates linearly（线性地）.§4 .1 动词不定式～1、普通不定式（3）表语*** Suppose that this milliammeter （毫安表）is to be used as an ammeter（安培表）with a full-scale deflection（满刻度偏转）of 2A.*** Several points are to be noted（注意）in connection with the circuit.§4 .1 动词不定式～1、普通不定式（3）表语*** Feedback control systems are to be found in almost every aspect of our daily environment.§4 .1 动词不定式～1、普通不定式注：若在句子的主语部分有实意动词“do”的任何形式时，作表语的不定式的标志“to”可以省去。

What … do is (to)～All that … do is (to)～The best way to do is (to)～The only thing we must do is (to)～§4 .1 动词不定式～1、普通不定式注：若在句子的主语部分有实意动词“do”的任何形式时，作表语的不定式的标志“to”可以省去。

All we need to do is measure the voltage across this resistor.What we can do is consider the input to be a sum of functions（函数）.§4 .1 动词不定式～1、普通不定式（4）定语①普通不定式作定语时，往往可表示“能够”或“将来”之意。

An ohmmeter is a device to measure resistance. [≈that can measure resistance] R is the resistance to be measured. [≈that will be measured]§4 .1 动词不定式～1、普通不定式（4）定语②不定式作定语时与被定词之间存在以下四种逻辑关系：A、主谓关系（可以是主动的，也可以是被动的，可扩展成定语从句，如上面两例）§4 .1 动词不定式～1、普通不定式B、动宾关系（可扩展成定语从句）There are two cases to consider. [≈that we shall consider]We now have four equations to solve. [≈that we shall solve]§4 .1 动词不定式～1、普通不定式C、不定式短语尾部的介词与介宾的关系（可扩展成定语从句）Will you please give me a sheet of paper to write on?[= on which to write ≈on which I can write]§4 .1 动词不定式～1、普通不定式Each member has a switch with which to indicate a YES or NO vote（投票）.*** An anchor point（抛锚处）refers to a place where[= at which]to secure（栓住）a ship with an anchor（锚）.§4 .1 动词不定式～1、普通不定式D、纯修饰关系（在某些抽象名词后，如：time, purpose, ability, tendency, way, aim, objective, attempt等等，一般为主动形式）The ability to do work is called energy.The purpose to write this book is to give the reader a brief introduction to electronic computers.§4 .1 动词不定式～1、普通不定式D、纯修饰关系（在某些抽象名词后，如：time, purpose, ability, tendency, way, aim, objective, attempt等等，一般为主动形式）We call the time to complete one cycle （周）the period of the sinusoid（正弦波）.§4 .1 动词不定式～1、普通不定式注：科技文中常出现下面这种逻辑上为目的状语的定语。

The use of trigonometry（三角学）to describe the electrical signal has proved very valuable for engineers.§4 .1 动词不定式～1、普通不定式（5）状语①在句首（一般只表示目的，译成“为了；要”）To operate a computer well, it is necessary to do a lot of practice.§4 .1 动词不定式～1、普通不定式（5）状语②在句尾：既可表示目的（可译成“来；以便于”），也可表示结果（可译成“而；以致于”）This device can be used to measure the strength of the signal.Many elements combine with hydrogen （氢）to form combustible（易燃的）liquids.§4 .1 动词不定式～1、普通不定式（5）状语②在句尾：既可表示目的（可译成“来；以便于”），也可表示结果（可译成“而；以致于”）In a free state, atoms usually combine together to form molecules（分子）.§4 .1 动词不定式～1、普通不定式（5）状语③构成固定短语或搭配关系in order to …too ～to …so as to …so ～as to …such as to …such ～as to …§4 .1 动词不定式～1、普通不定式（5）状语③构成固定短语或搭配关系require [use; need]to …sufficient(ly) [enough]to …able to …try to…aim to…act[serve;behave;function]to…§4 .1 动词不定式～1、普通不定式（5）状语③构成固定短语或搭配关系In a liquid, enough intermolecular （分子间的）forces exist to keep the volume of the liquid constant.§4 .1 动词不定式～1、普通不定式（5）状语③构成固定短语或搭配关系In long-distance communications, a transmitter is required to process the incoming information so as to make it suitable for transmission and subsequent （随后的）reception（接收）.§4 .1 动词不定式～1、普通不定式（5）状语③构成固定短语或搭配关系This section serves to introduce the subject of Communications Systems.§4 .1 动词不定式～1、普通不定式（6）补足语A net（净的）force applied to a body causes it to be accelerated（加速）.Ordinary matter is said to be electrically neutral（中性的）.“is said”= 被说成我们说据说§4 .1 动词不定式～1、普通不定式（6）补足语The science of electronics may be said to have begun with the discovery of electron tubes（管子）.★Let it be required to develop（展开）f(x) into a Fourier’s series（傅氏级数）.[关于动词不定式的功能图，请参见教材第138页。