When you analyze this light, you can figure out their distance from the Earth, and identify what they are made of, determine their chemical composition.
当你分析这些光的时候，你可以计算出它们与地球的距离，并确定它们由什么构成，查明它们的化学成分。
2
A figure stood in the doorway, silhouetted against the light.
门口站着一个人，屋里的亮光映衬出他的轮廓。
《牛津词典》
3
Use smoke for day (tires or petroleum products for dark smoke and green vegetation for light smoke). (Figure III-5)