Problem: Much of the early paper made from wood pulp contained significant amounts of alum, a variety of aluminium sulfate salts that is significantly acidic. Alum was added to paper to assist in sizing, making it somewhat water resistant so that inks did not "run" or spread uncontrollably. Early papermakers did not realize that the alum they added liberally to cure almost every problem encountered in making their product would eventually be detrimental. The cellulose fibres that make up paper are hydrolyzed by acid, and the presence of alum would eventually degrade the fibres until the paper disintegrated in a process that has come to be known as "slow fire". Documents written on rag paper were significantly more stable. The use of non-acidic additives to make paper is becoming more prevalent, and the stability of these papers is less of an issue.
How was rag paper inferior to the early types of paper made using alum?
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Answer: unanswerable

Problem: A cabinet of coins is the Munzkabinett der TUI-AG. The Polizeigeschichtliche Sammlung Niedersachsen is the largest police museum in Germany. Textiles from all over the world can be visited in the Museum for textile art. The EXPOseeum is the museum of the world-exhibition "EXPO 2000 Hannover". Carpets and objects from the orient can be visited in the Oriental Carpet Museum. The Blind Man Museum is a rarity in Germany, another one is only in Berlin. The Museum of veterinary medicine is unique in Germany. The Museum for Energy History describes the 150 years old history of the application of energy. The Home Museum Ahlem shows the history of the district of Ahlem. The Mahn- und Gedenkstatte Ahlem describes the history of the Jewish people in Hanover and the Stiftung Ahlers Pro Arte / Kestner Pro Arte shows modern art. Modern art is also the main topic of the Kunsthalle Faust, the Nord/LB Art Gellery and of the Foro Artistico / Eisfabrik.
What is a box of coins?
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Answer: unanswerable

Problem: Some of Jackson's successors made no use of the veto power, while others used it intermittently. It was only after the Civil War that presidents began to use the power to truly counterbalance Congress. Andrew Johnson, a Democrat, vetoed several Reconstruction bills passed by the "Radical Republicans." Congress, however, managed to override fifteen of Johnson's twenty-nine vetoes. Furthermore, it attempted to curb the power of the presidency by passing the Tenure of Office Act. The Act required Senate approval for the dismissal of senior Cabinet officials. When Johnson deliberately violated the Act, which he felt was unconstitutional (Supreme Court decisions later vindicated such a position), the House of Representatives impeached him; he was acquitted in the Senate by one vote.
How many of Johnson's fifteen vetoes did Congress override?
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Answer:
unanswerable