Problem: According to the United States Census Bureau, the city has a total area of 656.3 square miles (1,700 km2); this comprises 634.0 square miles (1,642 km2) of land and 22.3 square miles (58 km2) of water. The Piney Woods is north of Houston. Most of Houston is located on the gulf coastal plain, and its vegetation is classified as temperate grassland and forest. Much of the city was built on forested land, marshes, swamp, or prairie which resembles the Deep South, and are all still visible in surrounding areas. Flatness of the local terrain, when combined with urban sprawl, has made flooding a recurring problem for the city. Downtown stands about 50 feet (15 m) above sea level, and the highest point in far northwest Houston is about 125 feet (38 m) in elevation. The city once relied on groundwater for its needs, but land subsidence forced the city to turn to ground-level water sources such as Lake Houston, Lake Conroe and Lake Livingston. The city owns surface water rights for 1.20 billion gallons of water a day in addition to 150 million gallons a day worth of groundwater.
How is the vegetation of the area classified?
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Answer: temperate grassland and forest


Problem: Zinc is a chemical element with symbol Zn and atomic number 30. It is the first element of group 12 of the periodic table. In some respects zinc is chemically similar to magnesium: its ion is of similar size and its only common oxidation state is +2. Zinc is the 24th most abundant element in Earth's crust and has five stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest mineable amounts are found in Australia, Asia, and the United States. Zinc production includes froth flotation of the ore, roasting, and final extraction using electricity (electrowinning).
What is the most common zinc ore?
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Answer: sphalerite


Problem: France started the Franco-Prussian War (1870–71), and was defeated by the Kingdom of Prussia and other German states. The end of the war led to the unification of Germany. Otto von Bismarck annexed Alsace and northern Lorraine to the new German Empire in 1871; unlike other members states of the German federation, which had governments of their own, the new Imperial territory of Alsace-Lorraine was under the sole authority of the Kaiser, administered directly by the imperial government in Berlin. Between 100,000 and 130,000 Alsatians (of a total population of about a million and a half) chose to remain French citizens and leave Reichsland Elsaß-Lothringen, many of them resettling in French Algeria as Pieds-Noirs. Only in 1911 was Alsace-Lorraine granted some measure of autonomy, which was manifested also in a flag and an anthem (Elsässisches Fahnenlied). In 1913, however, the Saverne Affair (French: Incident de Saverne) showed the limits of this new tolerance of the Alsatian identity.
What war did Prussia start in 1870?
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Answer:
unanswerable