一张硬纸板a piece of cardboard在那个抽屉里有块硬纸板.There is a sheet of stiff cardboard in the drawer.沿着你的样板边画一圈，把图案描在一张硬纸板上。Trace around your template and transfer the design onto a sheet of card....
The systems are getting smaller and using lower voltages.这些系统变得更小，使用的电压也更低。The exact voltages used depend on the local supply.具体电压要视地区供电情况而定.However, high breakdown voltages necessarily need high - resistivity material.但...