telephoto camera lens
远摄照相机透镜

• pellucid
• pellucidity
• Peltier coefficient
• Peltier constant
• Peltier effect
• Peltier's element
• Peltier's heat
• penality function
• pencil
• pencil-beam light
• pencil-beam pattern
• pencil of rays
• pencil test
• pendant control
• pendulous
• pendulous gyroscope
• pendulum
• penertrating radiatio
• penetrability
• penetrating power
• penetrating wave
• penetration
• penetration frequency
• penetration of current
• penetraton depth