Science Buddies: "Ask an Expert"

Hi , Water the one substance we cannot live without. H2O.... H2 Hydrogen is highly explosive, and O Oxygen supports combustion. This sounds like an explosive mix yet when combined they form a life dependant source. How does this come to be, and how can I explain this to students.
Thanks for your help

tes hydrogen is explosive when combined with fire endind with harm to the living organism but when an flame is absent and oxygen starts to mix with hydrogen in the upper atmosphere creating a gas when hit by radiation from the sun forms ice that when it builds enough mass a it starts to fall when it gets to a certain point it simply melts creating rain that ends up in all our drinking water. so basically its just a mixture between hydrogen oxygen and small amount of radiation that burns up before it hits the ground