Chromabacterium biolaceum
[建] 紫色杆菌
🗣️ 情景例句
Where do I board my plane?
我在那儿登机？
I wrote several letters on my mother's behalf.
我代表我母亲写了几封信。
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。