“电力生产工作”包括电力设备（设施）的运行、检修维护、（）以及电力设备的更新改造、业扩、用户电力设备的安装、检修和试验、输煤、除灰等工作。 ["施工安装、试验","产品认证","生产性管理工作","质量评级"]
简述钢筋理论质量的计算公式。
机动车驾驶人饮酒后或者醉酒后驾驶机动车的记分分值为（） ["机动车驾驶人饮酒后记6分","机动车驾驶人醉酒后驾驶机动车记12分","机动车驾驶人饮酒后或者醉酒后驾驶机动车记12分"]
A temporary condition of danger will not make the port（）,provided that such condition will not last an unreasonable time. ["unsafe","safe","good","bad"]
Why are removable sleeves installed on centrifugal pump shafts?（） ["They make it easier to replace the pump shaft packing","They can be economically replaced as they wear out","They can be removed when it is necessary to lighten the weight of the pump","They increase the strength of the shaft"]
三毛金藻引起的中毒的原因是什么？
