单项选择题
A.winch B.crane C.derrick D.gantry
To avoid shock ,you should reduce speed by（）（低速）control...
单项选择题To avoid shock ,you should reduce speed by（）（低速）control.
A. low speed B. high speed C. inching D. slow speed
This is a（）（侧滚动）type hatch cover.A.foldingB.rollingC.si...
单项选择题This is a（）（侧滚动）type hatch cover.
A.folding B.rolling C.side-rolling D.unfolding
We need plenty of （）(绑扎钢丝).A. bridge platesB. bridge fi...
单项选择题We need plenty of （）(绑扎钢丝).
A. bridge plates B. bridge fittings C. twist locks D. lashing wires
