I have been a second-hand shop in Guangzhou for many years, mainly collecting some mobile phones, computers and camera PSP. After receiving it, give it to others. If you don't know how to do it, I personally think you'd better not do it. The water in it is very deep. The technical content is also very high. Because they are all second-hand, the simplest reason is that you think about the good things that others will give you. There are good things, but most of them come from abnormal places.