Context and question: Most copper is mined or extracted as copper sulfides from large open pit mines in porphyry copper deposits that contain 0.4 to 1.0% copper. Examples include Chuquicamata in Chile, Bingham Canyon Mine in Utah, United States and El Chino Mine in New Mexico, United States. According to the British Geological Survey, in 2005, Chile was the top mine producer of copper with at least one-third world share followed by the United States, Indonesia and Peru. Copper can also be recovered through the in-situ leach process. Several sites in the state of Arizona are considered prime candidates for this method. The amount of copper in use is increasing and the quantity available is barely sufficient to allow all countries to reach developed world levels of usage.
From what types of mines is copper extracted?
Answer: open pit mines
Context and question: According to the U.S. Census Bureau, in 2004, Miami had the third highest incidence of family incomes below the federal poverty line in the United States, making it the third poorest city in the USA, behind only Detroit, Michigan (ranked #1) and El Paso, Texas (ranked #2). Miami is also one of the very few cities where its local government went bankrupt, in 2001. However, since that time, Miami has experienced a revival: in 2008, Miami was ranked as "America's Cleanest City" according to Forbes for its year-round good air quality, vast green spaces, clean drinking water, clean streets and city-wide recycling programs. In a 2009 UBS study of 73 world cities, Miami was ranked as the richest city in the United States (of four U.S. cities included in the survey) and the world's fifth-richest city, in terms of purchasing power.
In what year did Miami's government declare bankruptcy?
Answer: 2001
Context and question: In the 14th century, much of the Greek peninsula was lost by the Byzantine Empire at first to the Serbs and then to the Ottomans. By the beginning of the 15th century, the Ottoman advance meant that Byzantine territory in Greece was limited mainly to its then-largest city, Thessaloniki, and the Peloponnese (Despotate of the Morea). After the fall of Constantinople to the Ottomans in 1453, the Morea was the last remnant of the Byzantine Empire to hold out against the Ottomans. However, this, too, fell to the Ottomans in 1460, completing the Ottoman conquest of mainland Greece. With the Turkish conquest, many Byzantine Greek scholars, who up until then were largely responsible for preserving Classical Greek knowledge, fled to the West, taking with them a large body of literature and thereby significantly contributing to the Renaissance.
At the start of 15th century, the biggest Byzantine city was what?
Answer:
Thessaloniki