状语从句、同位语从句

The statement (陈述) that resistance is equal to voltage divided by current is called Ohm’s law, since it was first verified (证实) experimentally by the German physicist George Ohm.
4.
provided (that) = if ● The machines will run well provided that they are greased in time .
这些机器只要及时上油，就会运转
得很好。





5. each time /every time / any time = whenever ● One linear factor appears each time a root is found. 每求出一个根，就会出现一个线性因子。 ● This product can be used any time you feel a sore throat coming on. 每当感觉喉咙疼痛时，就可使用该产品。



2. the use of “while” (1) meanwhile (2) concession (3) contrast (1) meanwhile 当……时候，在……期间 （从句多为进 行时态）
● While it is recording each purchase, the computer is also checking the store’s inventory(存货) for reordering purposes. 当计算机记录每笔买卖时，它同时还检查 商店的存货以便再次订购。


Just as the rate of flow of water between two points depends upon the difference of height between them, the rate of flow of electric current between two points depends upon the difference of potential (电位差)between them.

(3) There is every possibility that… ● There is every possibility that some kind of primitive life forms exist elsewhere in the solar system. 在太阳系的其它地方存在着某种原 始生命形式是完全可能的。
3. Some useful patterns (1) There is evidence that … ● There is evidence that this equation holds. (2) There is no doubt that… ● There is no doubt that the magnetic field is produced by some sort of circulating (循环的)electric current. 毫无疑问，磁场由某种循环电流产生。
books devoted to Pascal, this book differs from them in its basic philosophy（观点）. 尽管目前有许多书籍讲Pascal语言，不过 本书在基本观点方面与它们不同。
（注：PASCAL是一种结构程序设计语言,由瑞士苏黎世联 邦工业大学的沃斯(N.Wirth)教授研制,于1971年正式公布。 以法国数学家命名的Pascal语言现已成为使用最广泛的基 于DOS的语言之一，其主要特点有：严格的结构化形式； 丰富完备的数据类型；运行效率高；查错能力强。）

4. In some cases a noun clause may act as an appositive clause. In fact, a preposition such as “of, about , on” or “as to” is omitted ● At that time the scientist had no idea what steps he was to take to deal with that situation. 当时，那位科学家不知道该采取什么步 骤来处理这种情况。

● Even if no current is flowing, the voltage is there while the generator is operating. 当发电机在工作时，即使没有电流流动， 也存在着电压。


(2) concession

● While at present there are many

II. The appositive clause 1. The definition 2. General cases ● In this case, the condition that the function must exist is not satisfied. 在这种情况下，函数必须存在这一条件并没 有满足。 ● This is equivalent to a statement that everything is attracted by the earth. 这等于是说所有东西都受地球吸引。
电子绕原子核旋转，就像行星绕太阳运行一样。






④ 表示比较：“如……” ● This machine works as well as that one (does). ⑤ 表示让步：“虽然” （从句的一部分 要倒置于as之前） ● Small as they are, atoms are made of still smaller units. 原子虽小，却是由更小的单位构成。

Passage translation Nearly all substances fall into two major categories: conductors and insulators (绝 缘体). Metals, many liquids, and plasmas (等离子体) are conductors, while nonmetallic solids, certain liquids, and gases are insulators.
“因为；由于” ● The elements of Group II are also chemically similar, as each has two outer electrons(外层电子). 第2组的元素在化学性能上也类同，因为每 个元素均有两个外层电子。 ③ 表示方式：“如同”、“像……一样” ● Electrons move round the nucleus just as the planets move round the sun.


I. The adverbial clause
1. Special translation techniques for 2 patterns (1) …not until…



直到……（之后）才……
● The machine will not start to operate until it receives a signal. 这台机器直到收到信号后才开始工作。








3. the use of “as” ① 表示时间：“当……的时候”（主、 从 句的两个动作同时进行）；“随着” ● As t goes to infinity（无穷大）, f (t) goes to zero. 当t 趋于无穷大时， f(t)趋于零。 ● As the temperature of a body rises, the radiated heat also increases. 随着物体温度的上升，辐射的热量也 不断增加。



(2)…before… …… 后才……（顺译） ● The body will move on for some distance before it stops. 该物体将继续向前运动一段距离后才停下 来。 ● These values must be converted from the decimal system to binary system before the computation begins. 这些数值必须从十进制转换成二进制后才 能开始计算。