1, knowledge points refer to single independent questions or knowledge common sense, and knowledge lines refer to the * * * similarity that can be interconnected in a big knowledge, with a wide range of knowledge fields, and all knowledge connects the whole knowledge network. Therefore, connecting points into lines, connecting lines into planes and connecting them horizontally and vertically refers to the implication of knowledge, that is, the so-called profound meaning, multi-faceted thinking, positive and negative extension and so on.

2. For example, learning the knowledge of circle, its horizontal knowledge is other plane figures: rectangle, square, parallelogram, triangle, trapezoid and polygon.