Dihydrocaliciferol
二氢钙化甾醇, 二氢骨化醇
🗣️ 情景例句
Come on! You'll hear about it.
来吧， 来听听。
I remember the girl whose father goes there every summer.
我记得那个女孩的父亲每年夏天都去那里。
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。