style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/B）Paper can be made from an almost endless variety of cellulose-based material which will include many woods, cottons and grasses or which papyrus is an example and from where we get the word “paper”. Many of these are very specialized, but the preponderance of paper making has been from soft wood and cotton or rags, with the bulk being wood-based.
style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/ style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/C）In order to make wood into paper it needs to be broken down into fine strands. Firstly by powerful machinery and then boiled with strong alkalies such as caustic soda, until a fine pulp of cellulose fibers is produced. It is from this pulp that the final product is made, relying on the bonding together of the cellulose into layers. That, in a very small nutshell, is the essence of paper making from wood. However, the reality is rather more complicated. In order to give us our white paper and card, the makers will add bleach and other materials such as china clay and additional chemicals.
style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/D）A further problem with wood is that it contains a material that is not cellulose. Something called lignin. This is essential for the tree since it holds the cellulose fibres together, but if it is incorporated into the manufactured paper it presents archivists with a problem. Lignin eventually breaks down and releases acid products into the paper. This will weaken the bond between the cellulose fibers and the paper will become brittle and look rather brown and careworn. We have all seen this in old newspapers and cheap paperback books. It has been estimated that most paper back books will have a life of not greater than fifty years. Not what we need for our archives.
style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/E）Since the lignin can be removed from the paper pulp during manufacture, the obvious question is “why is it left in the paper?” The answer lies in the fact that lignin makes up a considerable part of the tree. By leaving the lignin in the pulp a papermaker can increase his paper yield from a tree to some 95%. Removing it means a yield of only 35%. It is clearly uneconomic to remove the lignin for many paper and card applications. It also means, of course, that lignin-free paper is going to be more expensive, but that is nevertheless what the archivist must look for in his supplies. There is no point whatsoever in carefully placing our valuable artifacts in paper or card that is going to hasten their demise. Acid is particularly harmful to photographic materials, causing them to fade and is some cases simply vanish!
style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/F）So, how do we tell a piece of suitable paper or card from one that is unsuitable? You cannot do it by simply looking, and rather disappointingly, you cannot always rely on the label.  "Acid-free" might be true inasmuch as a test on the paper may indicate that it is a neutral material at this time. But lignin can take years before it starts the inevitable process of breaking down, and in the conditions it will speed up enormously.
style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/G）Added to this, as I have indicated earlier, paper may also contain other materials added during manufacture such as bleach, china clay, chemical whiteners and size. This looks like a bleak picture, and it would be but for the fact that there are suppliers who will guarantee the material that they sell. If you want to be absolutely sure that you are storing in, or printing on, the correct material then this is probably the only way. Incidentally, acids can migrate from material to material. Lining old shoe boxes with good quality acid-flee paper will do little to guard the contents. The acid will get there in the end. 
style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/ style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/H）Paper is also commonly made from cotton and rag waste. This has the advantage of being lignin-free, but because there is much less cotton and rag than trees, it also tends to be much more expensive than wood pulp paper. You will still need to purchase from a reliable source though, since even rag paper and card can contain undesirable additives.
style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/I）A reliable source for quality rag papers is a recognized art stockiest. Many water color artists insist on using only fine quality rag paper and board. The main lesson to learn from this information is that you cannot rely on purchasing archival materials from the high street. The only safe solution is to purchase from specialist suppliers. It may cost rather more, but in the end you will know that your important and valuable data and images have the best home possible.

style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/B） Astrology differs from astronomy. Astrology developed from a set of principles that originated more than2, 000 years ago. At that time, astronomy was also based on those same principles. But during the l500’s and 1600’s, several astronomers, including Nicolaus Copernicus of Poland and Tycho Brahe of Denmark, made discoveries about the heavenly bodies that conflicted with the principles of astrology. As a result, astrology and astronomy became widely different in their methods and purposes. Today, astrologers observe the heavenly bodies to understand things that happen on the earth. Astronomers seek scientific knowledge about the various objects in space. 
style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/ style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/C） The basic principle of astrology is that the heavenly bodies influence what happens on the earth. Astrologers learn about this influence by casting(drawing)a circular chart called a horoscope or birth chart. A horoscope shows the position of the planets in relation to both the earth and the stars at a certain time. In most cases, it shows the position of these bodies at the time of a person’s birth. The system used by astrologers to cast a horoscope is based on a special view of the universe. This view involves four elements(1)the earth, (2)the planets, (3)the zodiac(黄道), and(4)the houses. The earth. In casting a horoscope, astrologers place the earth at the center of the solar system. Therefore, all heavenly bodies-revolve around the earth rather than around the sun. Astrologers use this arrangement to determine the positions of the heavenly bodies in relation to the earth. They believe that the study of the positions of the heavenly bodies can reveal a person’s character and future. 
style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/D） The planets. In astrology, the moon and the sun are considered planets, along with Jupiter, Mars, Neptune, Pluto, Saturn, Uranus, and Venus. Each planet supposedly represents a force that affects people in a certain way. Astrologers believe the planets influence a person more than do any other heavenly bodies. The zodiac is a band of stars that appear to encircle the earth. It is divided into12 equal parts, called signs. Each sign of the zodiac has certain characteristics, which are determined by a particular planet and other factors. Astrologers believe the signs determine how the planets affect a person’s character. The houses. Like the zodiac, the earth’s surface is divided into12 parts. Each of these parts, called houses, represents certain characteristics of an individual’s life. Astrologers believe the houses determine how the planets and the signs influence a person’s daily life. 
style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/ style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/E） Astrology began sometime before 2000 B. C. in Babylonia(now southeastern Iraq). Astrologers of that time knew of five planets—Jupiter, Mars, Mercury, Saturn and Venus. They believed that the sun, the moon, and planets sent out different forces, which had certain characteristics. For example, one of the planets—now known as Mars—appeared to be red. Astrologers linked it with anger, aggression and war. 
style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/F） The zodiac was probably developed in ancient Egypt, and the Babylonians adopted it sometime after l000 B. C. Astrologers gradually developed a system that linked seasonal changes with specific group of stars called constellations(星座). At that time, for example, heavy rainfall occurred in Babylonia when the sun was in a certain constellation. As a result, astrologers named the constellation Aquarius, the water bearer. 
style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/G） At first, astrologers studied the heavenly bodies in making general predictions about the future. But between 600 B. C. and 200 B. C. , they developed the system of casting individual horoscopes(以占星术算命). The ancient Greeks and Romans practiced astrology and greatly influenced its development. The Roman names for the planets and the signs of the zodiac are still used today. 
style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/H） Interest in astrology declined in Europe with the coming of Christianity as people sought guidance from religious leaders rather than from astrologers. Astrology regained popularity during the A. D. 1100’s. By the1600’s, it was particularly strong in England. Several astrological almanacs (历书)were published, and many other books either defended or attacked astrology. The number of followers of astrology fell in England during the 1700’s, but the subject’s popularity returned again in the early 1800’s. By the late 1800’s and early 1900’s, interest in astrology had spread to many other nations. Newspapers in England began publishing horoscope columns during the 1930’s. Such columns soon appeared in newspapers throughout the world, and people became increasingly interested in astrology. Today, astrology is followed more widely than ever before. 
style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/ style=margin: 0px; padding: 0px; color: rgb(51, 51, 51); font-family: 宋体; font-size: 14px; white-space: normal; background-color: rgb(255, 255, 255);/I） Many people believe astrology is simply a superstition, and scientists declare that its whole basis is unscientific. Scientists point out that the earth’s position has changed in space since ancient times. As a result, the signs of the zodiac used by astrologers no longer match the constellations for which they were named. Some people who believe in astrology support it in terms of magnetic fields, solar storms and other natural occurrences. Others, though they also believe in astrology, claim that it cannot be supposed scientifically. They consider it a set of powerful symbols that can provide a deep understanding of human beings. They defend astrology by pointing out that, in many cases, it works.