Lockfast
n. 保险箱\\na. 锁牢的
🗣️ 情景例句
Oh, how do you do?
噢 你好吗?
You must not pledge your own health.
切不可把健康作孤注一掷。
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。