句子成分的倒装（5）
（2）宾语从句提前 What an actual weight(实际重量) of the stone(石头) is we do not know and cannot compute(计算) until(直到) we know the pull(拉力) of gravity(重力) at the particular location(特殊位置) we are interested(感兴趣) in. How these filter circuits(滤波电路) work to smooth out(搞平滑) the pulsations(脉动) in the rectifier output(整流器输出) you will learn(学到) later on(以后).
2、作状语的介词短语提前的情况 The individuals concerned(有关人员) are too numerous(多) to mention(提及) but to all of them the author(作者) expresses(表示) his appreciation(感谢). To me it seems(似乎) that most students are interested in the practical applications(实际应用) of the subject areas(专业领域) they study. Of one thing we can be sure(肯定的): if the charges(电荷) are at rest(静止), there is no electric field(电场) at any point within(在…内部) the metal ball(金属球).
3、表语提前的情况（很少见） Certain(肯定的) it is that all essential(关键的) processes(过程) of plant(植物) growth(生长) and development(发育) occur(发生) in water.
4、谓语动词提前的情况（很少见） These particles(微粒) make up(构成) all the atoms in the universe(宇宙). Varies(变化)only their number(数目) and arrangement(排列), and it is the number and arrangement which give each atom its own characteristics(特性). Crash(撞车)trucks(汽车) sometimes do.
5、把较短的东西前置 最常见的是把宾语补足语（通常是几个形容词和“as”介词短语）和状语（一般是介词短语）放在较长的宾语前。 Electromagnetic waves(电磁波) make possible radio broadcast(无线电广播) and television. We call insulators these substances(物质) which prevent(阻止) the passage(通过) of electricity(电).
This equivalent resistance(等效电阻) could leave(使) unaltered(不变的)the potential difference(电位差) between the terminals(端点) of the combination(电阻组合) and the current in the rest(其余部分) of the circuit(电路). Only when we exert(施加) on an object(物体)an upward(向上的) force sufficient(足够的) in magnitude(数值) can we lift(提起) it. The oscillator(振荡器) maintains(维持) between its terminals (端点)a sinusoidal(正弦的) alternating(交变的) potential difference(电位差).