Carbon+Dioxide+D;

3 facts I found about __Carbon Dioxide__.


 * 1) It will support //combustion// of //magnesium// to give magnesium oxide and carbon.
 * 2) Although it is not a poison, it can cause death by suffocation if inhaled in large amounts.
 * 3) In some fire extinguishers, carbon dioxide is expelled through a nozzle and settles on the flame, smothering it.

Words you may want to know what they mean:
 * __Combustion__ - the act or process of burning.
 * __Magnesium__ - a light, ductile, silver-white, metallic element that burns with a dazzling white light.