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The Printed Word

        The earliest books were written on tablets of wood or pieces of bark. In Greeceand Rome, the tablets of wood were covered with wax, and writing was impressed upon them with a small stick called “stylus”. These tablets were held together on one side with thin strips of leather or metal rings. In Assyria and Babyloniaclay tablets were used for writing and the words were drawn with a piece of wood. After baking, the tablets were kept on shelves, just like books are kept today. Although the clay tablets didn’t look very beautiful, they were long-lasting and some of them survived until the present day. The earliest books of the ancient world were written on papyrus and skins of young animals. These books took the form of a long strip, rolled from one cylinder to another. These writings were known to the Romans as volumen  from which comes the word volume. Though paper has been known inChina since the first century, the secret of papermaking came toEurope much later.

        Books were quite common in ancientRome: we know that there were many booksellers and the first public library was founded there about 39 B. C. Only the rich could buy books or make their slaves copy books from important libraries. By the time of the Middle Ages all books were handwriting and often beautifully decorated. Libraries used to chain books to the shelves so that they could not be removed from the building. But very few people could read them. The invention of printing was a really great event in history. The first people to invent printing were the Chinese. InEuropethere were several people who can be called inventors of printing. The best-known is Johann Gutenberg fromGermany.

        Printing spread quickly over Europeand by the end of the 15th century there were more than 200 presses. The early printers were not only craftsmen, but also editors, publishers and booksellers. The first printing press inEngland was set up by William Caxton atWestminster in 1476, and the first printing press inRussia – by Ivan Fedorov inMoscow in 1564. Printed books soon reached a very high standard and the craftsmen were rightfully proud of their work. Eventually there were more and more people inEurope who could read and they wanted more and more books. That led to opening more libraries.

        Early libraries were used only by scientists and were few. By end by they grew in number and began to be used by the public. The 19th century saw the appearance of a proper system of public libraries. Now most countries have their own national libraries. Many old university libraries have rich collections of books: Oxford and Cambridge in England, Harvard and Yale in the United States. Among the great libraries of the world we can name the British Museum Library (The British Library) in London, the Library of Congress in the United States, Bibliotheque Nationale in France, the Beijing Library in China ,  the State Public Library in Moscow. The world’s largest is the US library of Congress. It holds about 90 million items – books and manuscripts. The library was founded in 1800 in Washington, DC for the use of Congress and later became a public library. Bibliotheque Nationale dates back to the 17th century and the British Museum Library was set in the 18th century. The State Public Library inMoscow was founded in 1862 and has unique collections of books.

        Modern libraries do their best to help people get information as quickly as possible. They use computers and electronic catalogues. Probably the most difficult problem for any library is to keep their books, journals and films. How they do it is a new story.

помогите ответить на вопросы по этому тексту.Вот вопросы:
What materials were used to make ancient books?
In what places of the world did people have books in ancient?
Where and when was printing invented?
By whom were early libraries used?
When did many public libraries appear?
What old universities have good libraries?
What cities of the world have great libaries?
 

Упростить выражения: 
1                6
____ -    ______
x - 3        x ² - 9

 
     a - 4                12a                    1
___________ + _________   -     ______ 
a ² + 4a + 16       a³ - 64                a - 4

решить пример 0,75 - ( 3/16 + 1/24)