单项选择题
Heavy cargo might break （）cargo, so it can’t be stowed on top of it.
A.light B.bulk C.dangerous D.wet
单项选择题 Cargo for （）No.4 is to be loaded first.
单项选择题 Bolts, nuts, split pins, hinges, wheels and stoppers should be frequently （）.
单项选择题 Before opening and closing the hatches, the spaces around the covers, all the parts and the gears should be （）.
