殡仪场所保洁的一般要求是什么?
关于船舶沉深横向力,下述正确的是:() ["当h<(0.65~0.75)D时,横向力明显增大(h:桨轴到水面的高度;D:螺旋桨直径)","船速越高,横向力越明显","右旋螺旋桨正车时,横向力推尾向左","正车横向力要比倒车时大"]
一类精神药品每张处方不得超过() ["A、7日常用量","B、2日常用量","C、3日常用量","D、2日极量"]
汽轮机船舶主机换向,从前进三到后退三约需时间为:() ["60-90s","90-120s","120-180s","180-240s"]
从前进三到后退三的换向操作时间最短的主机类型是:() ["蒸汽机船","内燃机船","汽轮机船","蒸汽机船与汽轮机船"]
殡仪服务员如何防护?