Nassa
abbr. National Aerospace Services Association 全国通信讨论会
🗣️ 情景例句
OK. Do you know when you'll come and visit?
好啊。你知道几时还会再来拜访我们吗？
How much does she need?
她需要多少？
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。