What would you uninvent?

What would you uninvent? The air-conditioner 

     Turning on air-conditioner and feeling the cool air are very easy, yet do you think about the effects which the air-conditioner causes? First, the air-conditioners cost a lot of money. Nowadays, the air-conditioners have been sold with lower and lower prices, and the advertisements always say that their products will help you reduce the electricity bills. That guarantee does not make sense. In my country, when I compare my electricity bills with the others, I find that the bills of families using the air-conditioner are always higher five times than the families having no air-conditioners. Clearly, you just spend a few of money to buy the air-conditioner, then you must pay more money for the monthly bills. Therefore, I think if you want to save money, the best method is stopping to use the air-conditioners.

     In addition, the air-conditioners are harmful for our environment. They make your houses, offices be cool, but they also eliminate the hot air into the atmosphere at that time. More and more people use the air-conditioners, hotter and hotter the air gets. Next, hotter and hotter people get, more and more people use the air-conditioners. As a result, this circle will be over and over and over again. For example, when I traveled to Singapore, the weather was not sunny but I still felt uncomfortable. Especially, when I walked around outside the high buildings, I felt so hot without sweating. I thought that was the result which the air-conditioners of the high buildings caused. 

     In short, the air-conditioners just give you a little of benefit which you can see immediately, but they will cause a lot of harmful problem which you have not think about yet.