reflecting square
反光直角器，反光直角块

• audiolocator
• Audiometer
• audion
• Audiovisual
• audio-visual instrument
• Au-doped
• Auer burner
• augend
• Auger Effect
• Auger recombination
• Auger transition
• augment
• augmented matrix
• Augustin Jean Fresnel
• aural
• aureole
• Aurora
• aurora australis
• aurora borealis
• auroral cap
• auroral emission
• auroral light
• Auroral Line
• auroral photometer
• auroral region