“重基础、考能力”,“源于课本、高于课本”,做到“两个有利”是高考命题的原则.因此,对课本进行合理的利用,特别是对课本习题进行挖掘、引申与改造显得尤为重要.下面以立体几何课本中的一道习题为例,看一看高考题是如何从课本习题改造得来的. “Take the basics and examine the ability”, “originate from the textbook, higher than the textbook”, and “two advantages” is the principle of the college entrance examination proposition. Therefore, make reasonable use of the textbook, especially the textbook excavation and extension. The transformation is particularly important. Here is an exercise in a three-dimensional geometry textbook as an example. Take a look at how the college entrance examination question has been transformed from textbook exercises.