定语从句（4）
“which”在定语从句中作“介词宾语”的情况 Ohm’s and Kirchhoff’s laws(定律) are the foundation(基础) on which all the other laws are built(建立). These stationary(静止的) objects(物体) are merely(仅仅) special(特殊的) cases(情况) in which the constant(恒定的) speed happens(碰巧) to be zero. They designed(设计) equipment(设备) by which people can utilize(利用) power(电力).
A magnet(磁铁) can cause(产生) an electric current in a wire(导线) near which it is moved(使运动). The body(人体) contains(容纳) a few large cavities(空腔) within which various(各种) organs(器官) are located(放置). ※This is a closed(闭合的) contour(等值线) on and within which there are no other singularities(奇点). 2、“短语介词+which”处于从句句首 Any mechanical(机械) device(装置) by means of which heat(热) is converted(转换) into work(功) is called a heat engine(热机).
Inertia(惯性) is that property(性质) of matter(物质) because of which a force must be exerted(施加) on a body(物体) in order to accelerate(使加速) it. The fundamental(基本的) principle(原理) in accordance with which all energy transformation(转换) in an electric circuit(电路) takes place(发生) has been already(已经) discussed.
Seismographs(地震仪) are based(基于) on the principle of inertia(惯性), according to which each body(物体) at rest(静止) tends(趋于) to preserve(保持) its state(状态) of rest. We keep(保持) all the variables(变量) of the function(函数) constant(不变的) except(除…外) one with respect to which we are differentiating(微分).