【正确答案】It is natural to ask why the Government makes this offer of protection under the patent law. The answer is in the Constitution itself, which provides that Congress may secure this right to inventors in order to promote the progress of the useful arts. The public benefits from this system for three reasons:
* First, the offer of patent protection encourages the inventor to make the invention
* Second, if the inventor succeeds with the help of the patent in developing and marketing the invention, the public is given the opportunity to use it;
* Third, since the inventor must describe the invention in the patent, and copies of the patent may be purchased by the public, then the knowledge of the invention is made available to everyone. If it were not for the patent law many inventors would be unable to develop their inventions and would abandon their ideas instead of going forward with them, and many others would keep them secret as long as they could, instead of publishing them in patents which stimulate others to make still further inventions.

【正确答案】* Papermaking. Chinese legend tells that the new invention of paper was presented to the Emperor in the year. Archeological evidence, however, shows that paper was in use two hundred years before then. Either way, the Chinese were significantly ahead of the rest of the world. The craft of papermaking relied upon an abundance of bamboo fiber to produce a fine quality paper. In China, the papermaker uses only the traditional materials and methods to produce fine art paper.
* Printing. The Chinese invention of moveable type, credited to the year 1045 AD, did not significantly impact Chinese society. Three hundred years later in Europe, Gutenberg's development of moveable type revolutionized the Western world. The Chinese language uses 3000 to 5000 characters in an average newspaper. The English language, in comparison, uses 26 characters in an average newspaper. Clearly, manipulating 5000 characters on a printing press took much longer than moving 26. Still, the invention of moveable type furthered Chinese technology and its role in the advancement of human civilization.
* Gunpowder. Imagine their enemy's surprise when the Chinese first demonstrated their newest invention in the eighth century AD. Chinese scientists discovered that an explosive mixture could be produced by combining sulfur, charcoal, and saltpeter (potassium nitrate). The military applications were clear. New weapons were rapidly developed, including rockets and others that were launched from a bamboo tube. Once again, the raw materials at hand, like bamboo, contributed ideas for new technologies.
Compass. By the third century AD, Chinese scientists had studied and learned much about magnetism in nature. For example, they knew that iron ore, called magnetite, tended to align itself in a North/South position. Scientists learned to "make magnets" by heating pieces of ore to red hot temperatures and then cooling the pieces in a North/South position. The magnet was then placed on a piece of reed and floated in a bowl of water marked with directional bearings. These first navigational compasses were widely used on Chinese ships by the eleventh century AD.