The use of DC electricity is another source of static electric fields, e.g. rail systems using DC, and televisions and computer screens with cathoderay tubes.
使用直流电是产生静电磁场的另一个原因，例如铁路系统使用直流电，电视和计算机屏幕带有阴极放射管。
2
A little more than 1.5 percent of each gold medal was made with metals harvested from cathoderay tube glass, computer parts, circuit boards and other trashed tech.