Light

I. Enumeration
A. Two general classifications of the sources of light
1.  natural sources 2.  artificial sources

B. Examples of heavenly bodies that give off light
1. sun 4.  aurora
2. moon         5.  stars
3. comets

C. Examples of luminescent creatures
1. angler fish 3.  firefly
2. jelly fish 4.

D. Examples of artificial sources
1. fluorescent lamp 5.  bonfire
2. oil lamp         6.  candle
3. kerosene lamp 7.  bulb
4. torch         8.  fire etc