单项选择题
A.operated B.operate C.operating D.operator
Is that all right at this（）?A.highB.heighC.heightD.high...
单项选择题Is that all right at this（）?
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
