Dotment
氧化铝
🗣️ 情景例句
I've been in China to work on the new project.
我一直在中国搞一个新项目。
Prepare for a rain day.
未雨绸缪。
and we have to lower into the ground and haul out of the ground great lengths of drill pipe which are rotated by an engine at the top and are fitted with a cutting bit at the bottom.
我们必须把很长的钻杆一节节地钻入地下，然后再从地下拉出来。钻杆顶部安装的发动机带动钻杆旋转，它的底部装有钻头。