opacity
(1)不透明性，阻光性
(2)不透明度，阻光度
(3)暗

• fission
• fissionable fuel
• fissure
• fit
• fit joint
• fit key
• fit keyway
• fit quality
• fitting
• fitting control
• fitting joint
• fitting surface
• fitting tight
• fitting-up
• fit tolerance
• fit-up
• fixation
• Fixation device
• fixed array multielment lidar
• fixed axis of rotation
• fixed base
• fixed beam
• fixed bias circuit
• fixed block
• fixed condenser