travelling-wave klystorn

例句：

1. 1.The travelling wave in the ocean is responsible for the currents.
   海洋中的旅行波负责形成洋流。
2. 2.The travelling wave in the microwave oven is responsible for its heating effect.
   微波炉中的旅行波负责其加热效果。
3. 3. The travelling wave in the laser is responsible for the cutting action.
   激光中的旅行波负责切割动作。