Coal-fired power plants The invention of the incandescent light bulb by Thomas A. Edison in 1879 c...
2009-10-03
American black bears American black bears appear in a variety of colors despite their name. In the...
The source of Energy A summary of the physical and chemical nature of life must begin, not on the ...
Statistics There were two widely divergent influences on the early development of statistical meth...
Obtaining Fresh water from icebergs The concept of obtaining fresh water from icebergs that are to...
Vision Human vision like that of other primates has evolved in an arboreal environment. In the den...
Sleep Sleep is part of a person’s daily activity cycle. There are several different stages of slee...
Bacteria Bacteria are extremely small living things. While we measure our own sizes in inches or c...
Folk Cultures A folk culture is a small isolated, cohesive, conservative, nearly self-sufficient g...
Cells and Temperature Cells cannot remain alive outside certain limits of temperature and much nar...