Analysis of a public-interest ad

 As we all know, smoking is a bad habit which does harm to you fitness by impairing  your lungs. Shown in this poster, the headline is "NO SMOKING",  which can tell you the purpose of this poster that is to appeal to the public not to smoke.

What's more, the picture used in this poster is that servel cigarettes are scorching the lung. The lung is put in the iron stand and the cigarettes below the iron stand look like a pile of match.the poster use this metaphor to show the public that the damage the lungs bearing made by the cigarettes is like to burn itself. The picture makes the damage of the lung  clearer which can give you a visual shock , wanning you that if you smoke that you lungs will burnt like this.

Besides, the smoking from the lung prints " NO SMOKING"  which lead to the headline of the poster. And the subheading of the poster "how long can you lungs bear?" point out the theme of the poster that smoking is bad to our health, especially to our lungs, so we have better to quit smoking.