Cells and Temperature Cells cannot remain alive outside certain limits of temperature and much narrower limits mark the boundaries of effective functioning. Enzyme systems of mammals and birds
Schooling and Education It is commonly believed in United States that school is where people go to get an education. Nevertheless, it has been said that today children interrupt their education to go
Plate Tectonics and Sea-floor Spreading The theory of plate tectonics describes the motions of the lithosphere, the comparatively rigid outer layer of the Earth that includes all the crust and part of
Folk Cultures A folk culture is a small isolated, cohesive, conservative, nearly self-sufficient group that is homogeneous in custom and race with a strong family or clan structure and highly d
Statistics There were two widely divergent influences on the early development of statistical methods. Statistics had a mother who was dedicated to keeping orderly records of government units (states
Lesson 4:Electricity The modern age is an age of electricity. People are so used to electric lights, radio, televisions, and telephones that it is hard to imagine what life would be like without them.
In the late eighteenth century, battles raged in almost every corner of Europe, as well as in the Middle East, south Africa ,the West Indies, and Latin America. In reality, however, there was only one
19.children's numerical skills people appear to born to compute. The numerical skills of children develop so early and so inexorably that it is easy to imagine an internal clock of mathematical maturi
The Salinity of Ocean Waters If the salinity of ocean waters is analyzed, it is found to vary only slightly from place to place. Nevertheless, some of these small changes are important. There are thre
Botany Botany, the study of plants, occupies a peculiar position in the history of human knowledge. For many thousands of years it was the one field of awareness about which humans had anything more t
Modern American Universities Before the 1850's, the United States had a number of small colleges, most of them dating from colonial days. They were small, church connected institutions whose pr
The Origin of Sports When did sport begin? If sport is, in essence, play, the claim might be made that sport is much older than humankind, for , as we all have observed, the beasts play. Dogs a
Types of Speech Standard usage includes those words and expressions understood, used, and accepted by a majority of the speakers of a language in any situation regardless of the level of formality. As
42.Coal-fired power plants The invention of the incandescent light bulb by Thomas A. Edison in 1879 created a demand for a cheap, readily available fuel with which to generate large amounts of
Movie Music Accustomed though we are to speaking of the films made before 1927 as "silent", the film has never been, in the full sense of the word, silent. From the very beginning, music was regarded
Piano The ancestry of the piano can be traced to the early keyboard instruments of the fifteenth and sixteenth centuries --- the spinet, the dulcimer, and the virginal. In the seventeenth century the
Suburbanization If by "suburb" is meant an urban margin that grows more rapidly than its already developed interior, the process of suburbanization began during the emergence of the industrial city in
The Historical Significance of American Revolution The ways of history are so intricate and the motivations of human actions so complex that it is always hazardous to attempt to represent events cover
The Beginning of Drama There are many theories about the beginning of drama in ancient Greece. The on most widely accepted today is based on the assumption that drama evolved from ritual. The argument
