Greatest mysteries in my head 2

Well...heres what i just started wondering about 1 day ago, that is H2o or also known as Water....

If im not mistaken, H20 is made out of oxygen and hydrogen. According to my science text book...oxygen is suppose to support combustion and hydrogen is suppose to be highly flamable, but, how can when both of these combine, they become something that puts out flames instead of making it worst, its kinda a weird thing if u ask me.

more teories coming up....now i gtg schl