Donutron
笼圈式谐振腔磁控管
🗣️ 情景例句
As a matter of fact,
事实上，
Fortune smiles upon the brave and frowns upon the coward.
幸运喜欢勇敢的人，而不喜欢怯懦的人。
the total absence of fishing boats around the oil rigs.
钻井平台周围根本没有捕鱼船只。