a concave mirror造句

• The diameter of a sphere is four times the focal length of a concave mirror cut from it
  凹面镜如果是从圆球上切下来的，圆球的直径会是凹面镜焦距的四倍。
• From gillens hairdressers window a composite portrait shows him gallant nelson s image . a concave mirror at the side presents to him lovelorn longlost lugubru booloohoom
  隔着吉伦理发店的窗户可以瞥见一帧综合照片16 ，映出纳尔逊的潇洒英姿。
• Renaissance craftsmen , moreover , would have faced severe technical challenges in silvering and sealing a concave mirror , which required the application of hot tar and pitch on the outside of the glass
  文艺复兴时代的工匠在涂银与装置凹面镜时，还要面对更多艰难的技术挑战，那需要在玻璃表面施予滚烫的焦油与沥青。
• For a number of historical and technical reasons , hockney envisions a camera obscura based not on a lens but on a concave mirror ( curved inward like a shaving or makeup mirror ) , which can also project an image onto a screen
  由于历史与技术上的若干理由，霍克尼推想出一种不采用透镜、却利用凹面镜的暗箱（凹面镜是一种内凹的镜子，比如刮胡子或化妆时用的镜子） ，这种镜子也可以把影像投射到屏幕上。
• A concave mirror reflects parallel light rays so that they meet at the so - called focal point . ( if you try to use such a mirror to start a fire in sunlight , you place the tinder at the focal point . ) the distance from the mirror to the focal point is its focal length
  凹面镜反射平行光，让光线汇聚到所谓的焦点（如果你想用这种镜子在日光下起火，就要把易燃物放在焦点上） ，从镜面到焦点的距离就是焦距。