I want to invent a kind of automatic schoolbag, you can't look down upon it, there are three buttons beside it, what is the use? Let me introduce you.
A button is a lot of use! As long as you press it, the weight in your bag will be lightened immediately, and you can easily go home when school is over. The second button will help you clean your bag without having to do it yourself. The third button will make you feel relaxed and happy as long as you press it.
The price of this kind of schoolbag is cheap, if you sell it at a high price, the function will disappear completely. I believe that with the development of science, through our efforts, it will become a reality.
