A. pushing B. lifting C. bothA.andB. D. noneoftheabove
A. seals B. cylinderhead C. cylindercap D. noneoftheabove
A. springforce B. load C. bothoftheabove D. noneoftheabove
A. oilforceismorethanspringforce B. oilforceislessthanspringforce C. oilforceandspringforcearesame D. noneoftheabove
A. longerextension B. smallerfoldedsize C. bothoftheabove D. noneoftheabove
A. onlytwostageunits B. onlythreestageunits C. twoorthreestageunits D. multi-stageunits
A. chemical energy B. hydraulic energy C. electricalenergy D. noneoftheabove
A. 对 B. 错
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