The red stuff that you often see being dropped from planes and helicopters is a chemical retardant that contains phosphate fertilizer, which helps to slow and cool down the fire.

• 通常你见到的从飞机和直升机上洒下的红色物质就是一种化学延缓剂，这种延缓剂含有磷肥，能够减缓和冷却火。