As we know, about 25000 people were killed in building fire in the world every year.Though firefighters are working so hard, death is still going on in building fire. Why are there always so many dead? Because, so far there are not any professional self-rescue instruments provided for the people. So when people are trapped in building fire, the only thing that they can do is just waiting for the firefighters` rescue. However, sometimes death always comes before rescue. If there is a...