The temperature in the upper part of the blast furnace (zone of reduction) is ______ that of the middle part

equal to

less than

more than

none of these

coal

coke

wood

producer gas

controls the grade of pig iron

acts as iron-bearing mineral

supplies heat to reduce ore and melt the iron

forms a slag by combining with impurities

controls the grade of pig iron

acts as iron-bearing mineral

supplies heat to reduce ore and melt the iron

forms a slag by combining with impurities

is used as a ballast for rail road

is mixed with tar for road making

consists of calcium, aluminum and ferrous silicates

all of the above