钻头+钻铤(易斜地层选用大钻铤或加重钻铤)+稳定器+钻铤+钻杆+方钻杆阀或方钻杆保护 发布时间:2017-07-04 11:57 │ 来源:www.tikuol.com 题型:单项选择题 问题: 钻头+钻铤(易斜地层选用大钻铤或加重钻铤)+稳定器+钻铤+钻杆+方钻杆阀或方钻杆保护接头+方钻杆的钻具组合为()。A、常规钻具组合B、满眼钻具组合C、钟摆钻具组合D、塔式钻具组合
题型:单项选择题 _____, there were also no lights in the houses along the street.[ ]A. There not only were no streetlights B. Not only there were no streetlightsC. Not only were there no streetlights D. There were only no streetlights 查看答案
题型:单项选择题 如图所示,半径为R光滑半圆形轨道竖直放置,与水平轨道相接于最低点.两个质量均为m的小球A、B以不同的速度进入轨道内,A通过最高点C时,对管道上部压力为3mg,B恰好通过最高点C,求A、B两球落地点间的距离. 查看答案