Prebasic
molt(鸟类每年繁殖期后的)大换羽
🗣️ 情景例句
Can I leave him a voice in mail?
我可以在他的语音信箱里留话吗？
My uncle was a pilot with the airlines.He just retired.
我的叔叔是航空公司的一名飞行员，他刚退休了。
and we control it by means of the mud which we circulate down the drill pipe.
我们让泥浆顺着钻杆向下循环，用这种方法来控制压力。