lens of variable focal length
可变焦聚透镜

• amperehour
• amperemeter
• ampere-turn
• amperite
• Amphoteric Materials
• amplidyne
• amplifer A
• amplification
• amplification coefficient
• amplification constant
• amplification factor
• amplification of light
• amplification ratio
• amplifier
• amplifier-inverter
• amplifier stage
• amplifying lens
• amplifying medium
• amplifying power
• amplifying system
• amplifying technique for light pulse
• amplifying tube
• amplifying valve
• amplitron
• amplitude