SDcamps•演辩营全国英语演讲与辩论赛
Plants in the Deserts Some cacti, like the saguaro, grow to tree size, but true trees need more moisture than most desert environments can supply, so they are scarce on deserts. Close to streambeds, cottonwoods can sometimes be found. Though these streams are dry most of the year, water flows there longest and is usually available fairly close to the surface. Elsewhere, tree...
The Organic Foods Are organically grown foods the best food choices? The advantages claimed for such foods over conventionally grown and marketed food products are now being debated. Advocates of organic foods — a term whose meaning varies greatly — frequently proclaim that such products are safer and more nutritious than others. The growing interest of consume...
First Inaugural Address We observe today not a victory of party, but a celebration of freedom, symbolizing an end, as well as a beginning; signifying renewal, as well as change. For I have sworn before you and Almighty God the same solemn oath our forebears prescribed nearly a century and three quarters ago. In your hands, my fellow citizens, more than in mine, will rest th...
Obtaining Fresh Water from Icebergs The concept of obtaining fresh water from icebergs that are towed to populated areas and arid regions of the world was once treated as a joke more appropriate to cartoons than real life. But now it is being considered quite seriously by many nations, especially since scientists have warned that the human race will outgrow its fresh water s...
Colds and Age A critical factor that plays a part in susceptibility to colds is age. A study done by the University of ichigan School of Public Health revealed particulars that seem to hold true for the general population. Infants are the most cold ridden group, averaging more than six colds in their first years. Boys have more colds than girls up to age three. After the age...
Animals’ Compasses Researchers have found that migrating animals use a variety of inner compasses to help them navigate. Some steer by the position of the Sun. Others navigate by the stars. Some use the Sun as their guide during the day and then switch to star navigation by night. One study shows that the homing pigeon uses the Earth’s magnetic fields as a guide ...
Raising Oysters In the past oysters were raised in much the same way as dirt farmers raised tomatoes – by transplanting them. First, farmers selected the oyster bed, cleared the bottom of old shells and other debris, then scattered clean shells about. Next, they “planted” fertilized oyster eggs, which within two or three weeks hatched into larvae. The larva...
树 我想我永远也不会看到 象一棵树那样优美的诗篇， 树那饥渴的嘴唇紧紧贴住 大地乳汁甘美的胸脯， 它整天仰望着上帝， 举起枝叶繁茂的手臂祈祷， 它那茂密如发的枝叶里 夏天会筑起知更鸟的安乐窝， 雪花飘落在它怀里， 它同雨水亲密无间。 诗歌出自我等愚人之手， 而树却是造化的天工。 乔埃斯·基尔默 (1) prest: pressed的变体，为了与下面一行最后一个词breast押韵而采用。 (2)flowing breast： 相当于b...
Plankton Scattered through the seas of the world are billions of tons of small plants and animals called plankton. Most of these plants and animals are too small for the human eye to see. They drift about lazily with the currents, providing a basic food for many larger animals. Plankton has been described as the equivalent of the grasses that grow on the dry land continents...
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 as an indispensable accompaniment; when the Lumiere films were shown at the first public film exhibition in the United States in February 1896, they were accompanied ...
The traditional holidays in our house when I was a child were spent timing elaborate meals around football games. My father tried to make pleasant chitchat and eat as much as he could during halftime. At Christmas he found time to have a cup or two of holiday cheer and do his holly-shaped bow tie1. But he didn’t truly shine until Valentine’s Day. I don’t kn...
A Curious Decision A poor chimney-sweeper, who had not enough money to buy a meal, stopped one hot summer day at noon before an eating-house, and remained regaling his nose with the smell of the victuals. The master of the shop told him several times to go away, but the sweep(1) could not leave the savory smell, though unable to purchase the taste of the food. At last the co...
The Early Settlers in North America The North American frontier changed some of the characteristics of the pioneers of the 1750’s and intensified others.They were, as a group, semiliterate, proud, and stubborn, as dogged in their insistence on their own way of life as pine roots cracking granite to grow.Perhaps their greatest resource was their capacity to endure. They...
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 electric power. Coal seemed to fit the bill, and it fueled the earliest power stations (which were set up at the end of the nineteenth century by Edison himself. As more power plants were...
The Source of Energy A summary of the physical and chemical nature of life must begin, not on the Earth, but in the Sun; in fact, at the Sun’s very center. It is here that is to be found the source of the energy that the Sun constantly pours out into space as light and heat. This energy is liberated at the center of the Sun as billions upon billions of nuclei of hydrog...
Bacteria Bacteria are extremely small living things. While we measure our own sizes in inches or centimeters, bacterial size is measured in microns. One micron is a thousandth of a millimeter: a pinhead is about a millimeter across. Rod-shaped bacteria are usually from two to four microns long, while rounded ones are generally one micron in diameter. Thus if you enlarged a r...
A little Girl Sitting on a grassy grave, beneath one of the windows of the church, was a little girl.(1) With her head bent back(2) she was gazing up at the sky and singing, while one of her little hands was pointing to a tiny cloud that hovered like a golden feather above her head. The sun, which had suddenly become very bright, shining on her glossy hair, gave it a metalli...
Scientific Theories In science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constan...
The History of Chemistry Chemistry did not emerge as a science until after the scientific revolution in the seventeenth century and then only rather slowly and laboriously. But chemical knowdedge is as old as history, being almost entirely concerned with the practical arts of living. Cooking is essentially a chemical process; so is the melting of metals and the administratio...
The Satiric Literature Perhaps the most striking quality of satiric literature is its freshness,its originality of perspective.Satire rarely offers original ideas.Instead, it presents the familiar in a new form. Satirists do not offer the world new philosophies.What they do is to look at familiar conditions from a perspective that makes these conditions seem foolish, harmful...