单词	f-number
释义	f-number noun f-num·​ber ˈef-ˌnəm-bər  1 : the ratio of the focal length to the aperture in an optical system 2 : a number following the symbol f/ that expresses the effectiveness of the aperture of a camera lens in relation to brightness of image so that the smaller the number the brighter the image and therefore the shorter the exposure required Word History Etymology focal length First Known Use 1898, in the meaning defined at sense 1
随便看	impoverishes impoverishing impoverishment impoverishments impower impowered impowering impowers impr impracticabilities impracticability impracticable impracticableness impracticablenesses impracticably impractical impracticalities impracticality impractically impracticalness impracticalnesses imprecate imprecated imprecates imprecating

英语词典包含469781条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。