短語詞組短語bar iron crane [機]鐵條起重機bar r crane 桿式起重機bar steel suspension crane 型懸掛行車Four -bar linkage of portal crane 門座起重機四連桿結(jié)構(gòu)four -bar linkage structure of crane 門機四連桿結(jié)構(gòu) 返回 bar crane