tank-driver's periscope
坦克驾驶员[潜望]镜

• parabolic mirror
• parabolic reflector
• parabolic-shaped collector
• paraboloid condenser
• paraboloid eyepiece
• paraboloid hyperholoid mirror
• paraboloid mirror
• paraconductivity
• paracrystalline array
• paraelectric phase transition
• paraffin
• parafocusing
• parafocusing arrangement
• parafocusing method
• parafocusing spectrometer
• parahboloidal mirror
• paraholoid
• para-hydrogen
• para-iodine
• parallactic
• parallactic angle
• parallactic displacement
• parallactic error
• parallax
• parallax correcting finder