overheat.
(7) A wire costs more than a silver wire. It is made of platinum.
一、被动语态的定语从句 2. 定语从句在主语以外的名词后面 例 (1) A saw is a tool which is used for cutting wood. (2) The figure shows an apparatus which can be used to measure the specific heat of metal. (3) The information is stored in a computer which is situated in a separate building. 练习2 将下列各组的两个句子改写成一个句子。 (1) Information about the weather comes from weather observation stations. They are found in every part of the world. (2) Recently, more general information has been transmitted by weather satellites. These are fixed in orbits. These keep them stationary in relation to the earth’s surface.
第六讲
含有大量情报的表达方式――定语从句
一、被动语态的定语从句 二、主动语态的定语从句 三、从句的缩短
一、被动语态的定语从句 1. 定语从句在主语后面，修ft in the sun. (条件/状况) An object become hot. （结果/原理）
一、被动语态的定语从句 3. 前置词 例 (1) Laboratories are rooms. Experiments are conducted in them. (2) Laboratories are rooms which experiments are conducted in. (3) Laboratories are rooms in which experiments are conducted. 注意：(2)(3)的语法都正确，但在科技英语中(3)较多。 练习3 从（ ）中选择正确的词组。 (1) The glass(which/from which/by which) retorts are made must be fire-proof. (from which) (2) There are several ways (for which/in which/of which) sunshine can be controlled to provide heat. (in which) (3) A container of hot water gives out heat to the objects (which/by which/in which) it is surrounded. (by which) (4) A drill is an instrument (on which/round which/with which) holes are made. (with which) (5) The process (for which/by which/which) plants build up glucose is called photosynthesis. (by which)
--> An object which is left in the sun becomes hot.
练习1 将下列各组的两个句子改写成一个句子。
(1) Iron can be shaped. Iron becomes red-hot.
(2) A bottle is dropped on a stone floor. It usually breaks into pieces.
一、被动语态的定语从句 4. [前置词＋wh-]的置换 (a) 在表示场所时，in which/at which where 例 Airports are places at which special attention is paid to the weather.
Airports are places where …
一、被动语态的定语从句 4. [前置词＋wh-]的置换
(b) By means of which whereby 例 A fuse-box is a device by means of which excessive loads are avoided. A fuse-box is a device whereby excessive load are avoided. (c) Of which whose 例 Venus (金星) is a planet of which the surface is thought to be at least 200 C. Venus is a planet whose surface temperature… 注意： whose可以用于人、物
(3) A balloon is filled with a gas lighter than air. It rises off the ground. (4) Paper is expensive. It is made from alfalfa. (5) Water is rarely pure enough to drink. It is taken from a river. (6) An engine is run at maximum speed for a long time. It may start to
Warehouses are places in which goods are stored. Warehouses are places where … 注意： The temperature at which water boils depends on the pressure 不能写为The temperature where… 理由？