Medium questions are often composed of several simple questions, and a difficult problem is often composed of several medium questions, from simple questions to medium questions, and then to difficult problems, not because a single solution step is particularly difficult, but a process of gradually complex improvement of a logical line.
If you go through the maze, the simpler the problem, the fewer forks in the road from condition to structure, and vice versa, the more complex the logical line, but no matter how complex the logical line is, it is also accumulated by more basic modules.
That's why learning should focus on the basics, and why in-class learning is the core.
The reason for this phenomenon is that although the middle questions are also wrong, they can understand it, or they can understand it by looking at the answers, so that they think that she has mastered the difficulty of this level, not that they will not, the gap is only in the solution of the problem, or through the improvement of the problem, the reverse makes the solution of the medium problem be improved, and the dimensionality reduction is realized.
However, this kind of problem is actually obviously disconnected from its existing level, that is, in the case of an unstable foundation, it takes more energy to understand this kind of problem, but this kind of understanding does not make its problem-solving ability to be improved, because the problem-solving process is scattered, and the so-called comprehension is only to remember the problem-solving process, and cannot form its own thinking system.
After mastering the basic questions, the problems of medium difficulty can be naturally dismantled, and the problems can be solved in an orderly manner, and after mastering the problems in the medium difficulty plates, the problems will be disassembled into small problems of medium difficulty and broken down, and the so-called super problems are split into two or even more difficult problems to solve.