在实际教学中，往往会出现这样的情况：学生的作业基本上能完成，甚至对“补视图、补漏线”一类也能做出来，但深入了解一下，很多同学并不知道自己画的图，特别是较为复杂的图所表达物体的空间立体形状，或者说缺乏综合想象能力，对学习“零件图、装配图”时问题就更为突出。 In the actual teaching, it often happens that the students’ assignments can basically be completed or even made up of a category like “supplementary view and missed-thread”. However, in-depth study shows that many students do not know the picture they have drawn , Especially the spatial three-dimensional shape of the objects represented by the more complex figures or the lack of comprehensive imagination, the problem becomes more conspicuous when learning “parts drawings and assembly drawings”.