Undulators
(undulator 的复数) [电] 波纹印码机
🗣️ 情景例句
Paper or plastic?
现金还是信用卡？
I had a glass of water.
我喝了一杯水。
Since the sea covers the greater part of the earth's surface,
既然海洋覆盖着地球的大部分表面，