定语从句（8）
“定语从句引导词的省略场合” 这种情况只能发生在限制性定语从句中。判断“引导词”在定语从句中被省略的最简单的方法，就是在一个大句子中有两个或多个并不等立的谓语（既没有任何等立连接词、又没有任何从句引导词）时，如果发现有两个紧挨着的、看起来互不相干的名词（或两个代词；或一个名词一个代词），就可知道这里边隐藏了定语从句，你就可以把这两个词分开来，定语从句就从后面那个词开始。
一、引导词在从句中作宾语 The amount(大小) of gravitational pull(万有引力) a body produces depends on the amount of material(物质) in it. Our National(国家) Bureau(局) of Standards (标准) now defines(定义) the second(秒) as the time it takes for an atom(原子) of cesium(铯) to make 9,192,631,770 internal(内部的) vibrations(振动). This component(部件) carries out (执行) the instructions(指令) we give it.
To satisfy(满足) this condition(条件), all we need do is shift(移动) the path (路径) of integration(积分) to the right (右边) of m. All clocks(时钟) do is cause(产生) interrupts(间断) at well-defined(规定好的) intervals(间隔). All the user has to do in order to access(访问) the records(记录) is start(启动) a web(网) browser(浏览器) and visit(访问) the web site(网址). These basic(基本的) rules(规则) are all we need to solve(解) a wide(广泛的) variety(种类) of network(网络) problems(题).
二、关系代词“which”在从句中作单个介词（而不是“by means of, in terms of, according to”等等短语介词）的介词宾语、而且“介词+which”在从句中作状语时可以省去（作定语时是绝对不能省的！），其条件是一定要把介词置于从句末尾（只有在这种情况下“which”也可以用“that”来代替）。不过在科技文中这种省略情况不多见，而大量出现在口语及科普文章中。 Power(功率) is the rate (速率) work(功) is done at. The resistance(电阻) of a conductor (导体) also depends on the substance(物质) it is made of.