Context and question: Copper occurs naturally as native copper and was known to some of the oldest civilizations on record. It has a history of use that is at least 10,000 years old, and estimates of its discovery place it at 9000 BC in the Middle East; a copper pendant was found in northern Iraq that dates to 8700 BC. There is evidence that gold and meteoric iron (but not iron smelting) were the only metals used by humans before copper. The history of copper metallurgy is thought to have followed the following sequence: 1) cold working of native copper, 2) annealing, 3) smelting, and 4) the lost wax method. In southeastern Anatolia, all four of these metallurgical techniques appears more or less simultaneously at the beginning of the Neolithic c. 7500 BC. However, just as agriculture was independently invented in several parts of the world, copper smelting was invented locally in several different places. It was probably discovered independently in China before 2800 BC, in Central America perhaps around 600 AD, and in West Africa about the 9th or 10th century AD. Investment casting was invented in 45004000 BC in Southeast Asia and carbon dating has established mining at Alderley Edge in Cheshire, UK at 2280 to 1890 BC. Otzi the Iceman, a male dated from 33003200 BC, was found with an axe with a copper head 99.7% pure; high levels of arsenic in his hair suggest his involvement in copper smelting. Experience with copper has assisted the development of other metals; in particular, copper smelting led to the discovery of iron smelting. Production in the Old Copper Complex in Michigan and Wisconsin is dated between 6000 and 3000 BC. Natural bronze, a type of copper made from ores rich in silicon, arsenic, and (rarely) tin, came into general use in the Balkans around 5500 BC.[citation needed]
When was copper last known to have been used?
Answer: unanswerable
Context and question: One year after its publication To Kill a Mockingbird had been translated into ten languages. In the years since, it has sold more than 30 million copies and been translated into more than 40 languages. The novel has never been out of print in hardcover or paperback, and has become part of the standard literature curriculum. A 2008 survey of secondary books read by students between grades 912 in the U.S. indicates the novel is the most widely read book in these grades. A 1991 survey by the Book of the Month Club and the Library of Congress Center for the Book found that To Kill a Mockingbird was rated behind only the Bible in books that are "most often cited as making a difference".[note 1] It is considered by some to be the Great American Novel.
Up til today, how many languages has To Kill a Mockingbird been printed in?
Answer: 40
Context and question: These immigrants were largely responsible for the first general strike in North America in 1835, in which workers in the city won the ten-hour workday. The city was a destination for thousands of Irish immigrants fleeing the Great Famine in the 1840s; housing for them was developed south of South Street, and was later occupied by succeeding immigrants. They established a network of Catholic churches and schools, and dominated the Catholic clergy for decades. Anti-Irish, anti-Catholic Nativist riots had erupted in Philadelphia in 1844. In the latter half of the century, immigrants from Russia, Eastern Europe and Italy; and African Americans from the southern U.S. settled in the city. Between 1880 and 1930, the African-American population of Philadelphia increased from 31,699 to 219,559. Twentieth-century black newcomers were part of the Great Migration out of the rural South to northern and midwestern industrial cities.
Who carried out the first strike in North America?
Answer:
immigrants