I think the most useful invention is the light.Edison invented it.It was invented in 1879.It’s invention more people playing and working hours.In addition to the lamp lighting can be used for addition there are many other uses.Flashlight,for example People can see things in the dark.Electric,the invention allows us to enter an era of light.Electric taught us many things which have to thank all of its inventor Edison.
我咋感觉这是课文啊?