Context and question: The terms asphalt and bitumen are often used interchangeably to mean both natural and manufactured forms of the substance. In American English, asphalt (or asphalt cement) is the carefully refined residue from the distillation process of selected crude oils. Outside the United States, the product is often called bitumen. Geologists often prefer the term bitumen. Common usage often refers to various forms of asphalt/bitumen as "tar", such as at the La Brea Tar Pits. Another archaic term for asphalt/bitumen is "pitch".
Where is bitumen the usual term for refined residue from crude oils?
Answer: United States
Context and question: In the 1970s, job losses due to industrial restructuring caused New York City to suffer from economic problems and rising crime rates. While a resurgence in the financial industry greatly improved the city's economic health in the 1980s, New York's crime rate continued to increase through that decade and into the beginning of the 1990s. By the mid 1990s, crime rates started to drop dramatically due to revised police strategies, improving economic opportunities, gentrification, and new residents, both American transplants and new immigrants from Asia and Latin America. Important new sectors, such as Silicon Alley, emerged in the city's economy. New York's population reached all-time highs in the 2000 Census and then again in the 2010 Census.
In what decade was there a significant decline in industrial jobs?
Answer: 1970s
Context and question: Alloying copper with tin to make bronze was first practiced about 4000 years after the discovery of copper smelting, and about 2000 years after "natural bronze" had come into general use[citation needed]. Bronze artifacts from the Vinča culture date to 4500 BC. Sumerian and Egyptian artifacts of copper and bronze alloys date to 3000 BC. The Bronze Age began in Southeastern Europe around 3700–3300 BC, in Northwestern Europe about 2500 BC. It ended with the beginning of the Iron Age, 2000–1000 BC in the Near East, 600 BC in Northern Europe. The transition between the Neolithic period and the Bronze Age was formerly termed the Chalcolithic period (copper-stone), with copper tools being used with stone tools. This term has gradually fallen out of favor because in some parts of the world the Chalcolithic and Neolithic are coterminous at both ends. Brass, an alloy of copper and zinc, is of much more recent origin. It was known to the Greeks, but became a significant supplement to bronze during the Roman Empire.
What started about 3000 years after copper smelting was discovered?
Answer:
unanswerable