Bipropargyl
联丙炔
🗣️ 情景例句
Take care, and have a nice flight.
请保重！祝你一路顺风！
Please tell us the Article Number of the Product.
请您把商品货号告诉我们。
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。