常見例句雙語例句Do not throw objects off the floor, mast or derrick.不允許從鉆臺上或井架上,往下亂扔?xùn)|西。blog.sina.com.cnTools carried into the derrick or mast should be secured to the body.帶到井架上的工具應(yīng)當(dāng)綁在身上。blog.sina.com.cnThe frame of mast derrick that is designed for hydraulic wheel tractor hoist adopt welding of armor plate, its section is oblong armor plate, and its material is HG60.為滿足液壓輪式通井機的使用要求而設(shè)計的桅桿式井架采用板焊結(jié)構(gòu), 主體截面為長方形的方形鋼, 材料為HG60。 返回 derrick mast