What are the tutorials on how to find things in the circle?

You can't find the key by drawing a circle. It's fake to circle for something.

First, think back to the scene of the last time I saw the key, and then think about what I did later. It is very likely that I took it in my hand and put it down after doing something.

Keys are common unlocking tools in people's lives. The main materials for making keys are copper, zinc, aluminum, iron and other metals. Keys were invented later than locks and appeared in ancient Egypt 4000 years ago. There are many kinds of keys, including ordinary keys, intelligent key, remote control keys, electronic keys and so on.

Related origin

When primitive people lived in caves, for the sake of safety, they sometimes pushed boulders to block the mouth of the cave, to guard against not thieves but wild animals. After the emergence of private ownership, thieves appeared and locks were born. As early as 3000 years ago, China had locks.

But the earliest locks had no mechanism, but were made in the shape of fierce animals such as tigers. In order to scare away thieves, they could only be said to be symbolic locks. It is said that Lu Ban was the first person to lock the lock. According to unearthed cultural relics and written records, ancient locks worked by the elasticity of two leaf springs. Until now, this spring is still in use.