Prewelding
预焊
🗣️ 情景例句
I don't know about that.
我表示怀疑。
First, I coundn't keep up with all the paperwork at the office.
首先我应付不了办公室的文书工作。
the graphic record shows three waves arriving one after the other at short intervals.
曲线纪录就能显示出前后相间的这3种地震波。