tangent
(tan tg)
(1)正切[的]
(2)切线[的]

• octonary
• octovision
• ocular
• ocular circle
• Ocular esthesiometer
• ocular micrometer
• Ocular pressure applicator
• ocular surface
• sliding key
• sliding-lens compensator
• sliding motion
• sliding mount
• sliding support
• sling
• slip ga(u)ge
• slipper
• slipping
• slit
• slit aperture
• slit beam
• slit camera
• slit diaphragm
• slit image
• slit jaws
• slit lamp