Spiratron
旋束管(离心静电聚焦行波管), 径向聚束行波管, 螺旋管
🗣️ 情景例句
We will help your children in learning lessons in their free time.
我们可以帮助您的孩子在他们空闲时学习功课。
Nothing is impossible to willing mind (or heart).
有志者事竟成。
It's David Chou.
周大卫。