Problem: Alloy:

Some alloys occur naturally, such as electrum, which is an alloy that is native to Earth, consisting of silver and gold. Meteorites are sometimes made of naturally occurring alloys of iron and nickel, but are not native to the Earth. One of the first alloys made by humans was bronze, which is made by mixing the metals tin and copper. Bronze was an extremely useful alloy to the ancients, because it is much stronger and harder than either of its components. Steel was another common alloy. However, in ancient times, it could only be created as an accidental byproduct from the heating of iron ore in fires (smelting) during the manufacture of iron. Other ancient alloys include pewter, brass and pig iron. In the modern age, steel can be created in many forms. Carbon steel can be made by varying only the carbon content, producing soft alloys like mild steel or hard alloys like spring steel. Alloy steels can be made by adding other elements, such as molybdenum, vanadium or nickel, resulting in alloys such as high-speed steel or tool steel. Small amounts of manganese are usually alloyed with most modern-steels because of its ability to remove unwanted impurities, like phosphorus, sulfur and oxygen, which can have detrimental effects on the alloy. However, most alloys were not created until the 1900s, such as various aluminium, titanium, nickel, and magnesium alloys. Some modern superalloys, such as incoloy, inconel, and hastelloy, may consist of a multitude of different components.

What is electrum made of?
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A: silver and gold

Problem: Solar energy:

Solar power is anticipated to become the world's largest source of electricity by 2050, with solar photovoltaics and concentrated solar power contributing 16 and 11 percent to the global overall consumption, respectively.

When is solar power is foreseen to become the largest source of electricity?
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A: 2050

Problem: Steven Spielberg:

Drawing from his own experiences in Scouting, Spielberg helped the Boy Scouts of America develop a merit badge in cinematography in order to help promote filmmaking as a marketable skill. The badge was launched at the 1989 National Scout Jamboree, which Spielberg attended, and where he personally counseled many boys in their work on requirements. That same year, 1989, saw the release of Indiana Jones and the Last Crusade. The opening scene shows a teenage Indiana Jones in scout uniform bearing the rank of a Life Scout. Spielberg stated he made Indiana Jones a Boy Scout in honor of his experience in Scouting. For his career accomplishments, service to others, and dedication to a new merit badge Spielberg was awarded the Distinguished Eagle Scout Award.

What Boy Scout merit badge did Spielberg help develop?
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A: cinematography

Problem: Dutch Republic:

In theory, the stadtholders were freely appointed by and subordinate to the states of each province. However, in practice the princes of Orange of the House of Orange-Nassau, beginning with William the Silent, were always chosen as stadtholders of most of the provinces. Zeeland and usually Utrecht had the same stadtholder as Holland.

Which states had the same stadtholder as Holland?
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A:
Zeeland and usually Utrecht