升降是指用起重机械吊起货物，通过垂直运动实现装卸。Lifting up and down refers to lifting goods with lifting machinery, loading and unloading are realized

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• 起重机械是指采用吊钩等起重工具，在间歇、重复的工作方式下，吊起、降低、举起、运输货物的机械设备。Hoisting machinery refers to the mechanical equipment that lifts, lowers or lift