Why can't both sides of the second-order Rubik's Cube be restored?

Figure 1 Since the second-order Rubik's Cube has no central block as a reference, we assume that it has a central block. For example, in the first step, we randomly find a corner block with white, and put the white face down. At this time, we assume that the direction of white flour is white flour and the color of white flour is yellow. Knowing these basic knowledge, we will restore the second-order Rubik's Cube with the ideas and formulas of restoring the third-order Rubik's Cube. In this step, we will introduce two basic formulas. If what you want to accomplish at present is exactly the same as figure 1- 1 or 1-2, just use the formula directly. If it is the case of Figure 10 1, 103, please follow the instructions. Figure 1- 1 Figure 1-2 Formula 2- 1: (r ur') Formula 2-2: (f' u' f) Memory skills: white face turns right, the first step is to rotate the right layer. Memory skills: white face turns forward, the first step is to rotate the front layer diagram 60. The above two positions "position A" and "position B" are called "standard positions", that is, 1 corner blocks on the bottom surface have been returned, and the other three corner blocks need to be exchanged. "Position C" can be corrected to the standard position by a certain rotation. After the subject judges which position it belongs to, the following can be restored by using the corresponding transformation method according to the actual situation. 2. Standard posture. The corner block with the correct bottom position is placed in the right front corner, and the other three corner blocks need to be reversed counterclockwise/clockwise. 3. Correct to the standard position. The position angle, that is, the position of the bottom four corner blocks is incorrect. At this time, the standard position can be converted into the standard position by arbitrarily using the A conversion method or the B conversion method of the standard position. The above is the face first method, which is a method to quickly restore the second-order Rubik's cube. Compared with other solutions, the threshold is lower and easier to understand. There are many websites for playing Rubik's Cube skills, but I really want to make one myself. I always feel that what I do will be different from others and may make my own characteristics. In short, I think as long as you do something seriously, you will always have a good experience. I have a Rubik's cube since I was a child, but I have never played it once. A few months ago, I came across a foreign web page occasionally. I suddenly realized that it is so simple to play the Rubik's Cube, and I usually don't have time, mainly on the bus and subway. I find this a very good thing. I often look up after restoring a Rubik's cube and find that the eyes of a trunk person are all on you:) Slowly, I also learned other Rubik's cube skills and Rubik's cube solutions. More importantly, I have met many friends who play Rubik's Cube. I found that many friends who play Rubik's Cube are enthusiastic and interesting people.