锅炉停炉操作应按次序进行。锅炉正常停炉时先停燃料供应，随之停止送风，降低引风。与此同时，逐渐降低锅炉负荷，相应地（）锅炉上水，但应维持锅炉水位（）正常水位。 ["减少；稍低于","减少；稍高于","增加；稍低于","增加；稍高于"]
请问焦炉砌筑的质量要求是什么？
食用菌是由营养菌丝和（）组成。
Prior to lighting off a cold automatically fired auxiliary boiler, you should （）. ["check and regulate the water level","close the air cock once fires are lit","blowdown the gage glass","crack the steam stop to assure protective steam flow"]
满堂脚手架搭设高度超过12m时，在顶层和竖向每隔（）步应设置连续的水平剪刀撑。 ["A.5","B.4","C.3","D.2"]
简述烂尾病的病原。
