oblique dark ground ilumination
倾斜暗场照明

• ohmmeter
• Ohm's law
• ohthalmo-eikonometer
• ohthalmological
• oil basin
• oil bath
• oil bearing
• oil damping
• oil diffusion pump
• oiless bearing
• oil film light value
• oil filter
• oil-imersion objective
• oil-immersion bath
• oil-immersion diffractometer
• oiliness
• oiling
• oilkjproof
• oil-quenched
• oil-sealed
• oilstone
• old sight
• ombination IR-laser trackerranger
• ombination square
• omegatorn