单选题Which condition is necessary for a substance to burn?（）AThe temperature of the substance must be equal to or above its fire pointBThe air must contain oxygen in sufficient quantityCThe mixture of vapors with air must be within the explosive rangeDAll of the above
单选题
Which condition is necessary for a substance to burn?（）
A
The temperature of the substance must be equal to or above its fire point
B
The air must contain oxygen in sufficient quantity
C
The mixture of vapors with air must be within the explosive range
D
All of the above
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