单项选择题
A.high B.heigh C.height D.higher
What’s the （）of the derrick?A.SLWB.LSWC.SWLD.FWE
单项选择题What’s the （）of the derrick?
A.SLW B.LSW C.SWL D.FWE
“SWL” means （）.A. safe working loadB. safe work loadC. ...
单项选择题“SWL” means （）.
A. safe working load B. safe work load C. safe worked load D. safely working load
（）do you want the derrick adjusted?A.WhatB.WhereC.HowD....
单项选择题（）do you want the derrick adjusted?
A.What B.Where C.How D.When
