焦点: 1.[数学] [物理学] (二次曲线焦点; 主焦点) focal point; focus 短语和例子虚焦点 virtual focus; 主焦点 principal focus; 焦点分散 defocus2.(问题的关键所在或争论的集中点) central issue; centre; point at issue 短语和例子斗争的焦点 the focus of the
阶梯楔块校准底片: step-wadge calibration filmstep-wadgecalibrationfilmstwadge calibration film