You stare at waterfall for a minute or two, and then shift your gaze to its surroundings. What you now see appears to drift upward.These optical illusions occur because the brain is constantly matchin
Art is considered by many people to be little more than a decorative means of giving pleasure. This is not always the case, however; at times, art may be seen to have a purely functional side as well.
Everyone has a moment in history, which belongs particularly to him. It is the moment when his emotions achieve their most powerful sway over him, and afterward when you say to this person “the worl
Is language, like food, like food, a basic human need without which a child at a critical period of life can be starved and damaged? Judging from the drastic experiment of Frederick I in the thirteent
Racket, din clamor, noise, whatever you want to call it, unwanted sound is America’s most widespread nuisance. But noise is more than just a nuisance. It constitutes a real and present danger to peo
Science is a dominant theme in our culture. Since it touches almost every facet of our life， educated people need at least some acquaintance with its structure and operation. They should also have a
Plastics are materials which are softened by heat and set into lasting form when shaped in a mold. Some are natural; some are semi-synthetic(半合成的) , the result of chemical action on natural su
Laziness is a sin(罪), everyone knows that. We have probably all had lectures pointing out that laziness is immoral, that it is wasteful, and that lazy people will never amount to anything in life. B
There are various ways in which individual economic units can interact with one another. Three basic ways may be described as the market system， the administered system， and the traditional system
The American economic system is organized around a basically private-enterprise， market-oriented economy in which consumers largely determine what shall be produced by spending their money in the ma