drawing
(1)抽，拉，压延
(2)牵引
(3)提取
(4)回火
(5)绘图

• persistence
• persistence of vison
• persistence time
• persisten wave
• personal error
• perspecitivity
• perspective axis
• perspective drawing
• perspective figure
• perspective geometry
• perspective view diagram
• perspex
• perturabance
• perturabation
• perturbation potential
• perturbation theory
• perturbation wave
• perturbed triplet
• perverted image
• peta
• petrographic microscope
• Petzval condition
• Petzval curvature of field
• Petzval lens
• Petzval protrait objective