什么是挡墙温度，该参数有何作用？
参考答案：
烟气在辐射室隔墙处或辐射室进入对流室时的温度，称挡墙温度，该参数是加热炉操作设计中一个重要工艺参数
A high-velocity fog stream can be used in fire fighting situations to drive heat and smoke ahead of the fire fighters in a passageway. This technique should only be used when（）.
A.using a 2-1/2 inch hose
B.there is an outlet for the smoke and heat
C.the fire is totally contained by the ship's structure
D.at least two fog streams can be used
给木本植物施肥常用的方法是（）。
A.撒施
B.条施
C.根外追肥
D.环状施肥
