Many public places, such as scenic spots, hospitals, parks and amusement parks, will sell all kinds of balloons. When I was a child, I had no resistance to these colorful balloons and wanted them every time I saw them. Today’s balloons are more likely to tempt children and have become various cartoon characters. Many passing children pester adults to buy one. But you know what? Such a lovely balloon may become a [devil] at any time! Balloon Hides Danger To make the balloon fly, it is usually filled with hydrogen or helium, because the density of both gases is less than that of air, so it can float in the air. Hydrogen balloons: But hydrogen balloons are very dangerous, because Read More …