Plasma is a gas that creates an electromagnetic field.

等离子体是一种能产生电磁场的气体。

One of the things going on outside your head is the electromagnetic field.

在你头脑之外发生的事情之一就是电磁场。

Understand the electromagnetic and gravitational fields of the planet.

了解行星的电磁场和引力场。

Crews are taking soil samples, flying drones and helicopters with transmitters to measure the electromagnetic field of the subsurface and map the layers of rock below.

工作人员正在采集土壤样本，操纵带有信号发射器的无人机或驾驶直升机来检测地下电磁场，并绘制岩层图。