When does auxiliary burner of incinerator put into operation? （）<br /> Ⅰ. start incinerator when it is cold<br /> Ⅱ. the sludge for dealing with is little<br /> Ⅲ. the sludge for dealing with is large<br /> Ⅳ. the water and impurity in sludge are too much<br /> Ⅴ. the temperature in incinerator is low<br /> Ⅵ. dealing with little solid rubbish<p> When does auxiliary burner of incinerator put into operation? （）<br /> Ⅰ. start incinerator when it is cold<br /> Ⅱ. the sludge for dealing with is little<br /> Ⅲ. the sludge for dealing with is large<br /> Ⅳ. the water and impurity in sludge are too much<br /> Ⅴ. the temperature in incinerator is low<br /> Ⅵ. dealing with little solid rubbish</p>