Here is a question about this article: The world's largest deposit of natural bitumen, known as the Athabasca oil sands is located in the McMurray Formation of Northern Alberta. This formation is from the early Cretaceous, and is composed of numerous lenses of oil-bearing sand with up to 20% oil. Isotopic studies attribute the oil deposits to be about 110 million years old. Two smaller but still very large formations occur in the Peace River oil sands and the Cold Lake oil sands, to the west and southeast of the Athabasca oil sands, respectively. Of the Alberta bitumen deposits, only parts of the Athabasca oil sands are shallow enough to be suitable for surface mining. The other 80% has to be produced by oil wells using enhanced oil recovery techniques like steam-assisted gravity drainage.
What is the answer to this question: What formative period  produced bitumen?
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So... early Cretaceous


Here is a question about this article: Despite competition from other materials, copper remains the preferred electrical conductor in nearly all categories of electrical wiring with the major exception being overhead electric power transmission where aluminium is often preferred. Copper wire is used in power generation, power transmission, power distribution, telecommunications, electronics circuitry, and countless types of electrical equipment. Electrical wiring is the most important market for the copper industry. This includes building wire, communications cable, power distribution cable, appliance wire, automotive wire and cable, and magnet wire. Roughly half of all copper mined is used to manufacture electrical wire and cable conductors. Many electrical devices rely on copper wiring because of its multitude of inherent beneficial properties, such as its high electrical conductivity, tensile strength, ductility, creep (deformation) resistance, corrosion resistance, low thermal expansion, high thermal conductivity, solderability, and ease of installation.
What is the answer to this question: How much of mined copper is used for cables and electrical wiring?
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So... Roughly half


Here is a question about this article: The surface bedrock under the Miami area is called Miami oolite or Miami limestone. This bedrock is covered by a thin layer of soil, and is no more than 50 feet (15 m) thick. Miami limestone formed as the result of the drastic changes in sea level associated with recent glaciations or ice ages. Beginning some 130,000 years ago the Sangamonian Stage raised sea levels to approximately 25 feet (8 m) above the current level. All of southern Florida was covered by a shallow sea. Several parallel lines of reef formed along the edge of the submerged Florida plateau, stretching from the present Miami area to what is now the Dry Tortugas. The area behind this reef line was in effect a large lagoon, and the Miami limestone formed throughout the area from the deposition of oolites and the shells of bryozoans. Starting about 100,000 years ago the Wisconsin glaciation began lowering sea levels, exposing the floor of the lagoon. By 15,000 years ago, the sea level had dropped to 300 to 350 feet (90 to 110 m) below the contemporary level. The sea level rose quickly after that, stabilizing at the current level about 4000 years ago, leaving the mainland of South Florida just above sea level.
What is the answer to this question: How many meters thick is the bedrock under Miami at its maximum?
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So...
15