The problem: Answer a question about this article:
The Protestant movement began to diverge into several distinct branches in the mid-to-late 16th century. One of the central points of divergence was controversy over the Eucharist. Early Protestants rejected the Roman Catholic dogma of transubstantiation, which teaches that the bread and wine used in the sacrificial rite of the Mass lose their natural substance by being transformed into the body, blood, soul, and divinity of Christ. They disagreed with one another concerning the presence of Christ and his body and blood in Holy Communion.
What Catholic belief did early Protestants not agree with?
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The answer: transubstantiation

The problem: Answer a question about this article:
After the Dambusters raid in 1943 an entirely new system was developed that was required to knock down any low-flying aircraft with a single hit. The first attempt to produce such a system used a 50 mm gun, but this proved inaccurate and a new 55 mm gun replaced it. The system used a centralised control system including both search and targeting radar, which calculated the aim point for the guns after considering windage and ballistics, and then sent electrical commands to the guns, which used hydraulics to point themselves at high speeds. Operators simply fed the guns and selected the targets. This system, modern even by today's standards, was in late development when the war ended.
What replaced the 50 millimeter gun that was not accurate?
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The answer: a new 55 mm gun

The problem: Answer a question about this article:
The popularity of this particular representation of The Immaculate Conception spread across the rest of Europe, and has since remained the best known artistic depiction of the concept: in a heavenly realm, moments after her creation, the spirit of Mary (in the form of a young woman) looks up in awe at (or bows her head to) God. The moon is under her feet and a halo of twelve stars surround her head, possibly a reference to "a woman clothed with the sun" from Revelation 12:1-2. Additional imagery may include clouds, a golden light, and cherubs. In some paintings the cherubim are holding lilies and roses, flowers often associated with Mary.
What does Mary stand upon in this symbol?
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The answer: moon is under her feet

The problem: Answer a question about this article:
Air quality in Boston is generally very good: during the ten-year period 20042013, there were only 4 days in which the air was unhealthy for the general public, according to the EPA.
Who determined that the air quality was unhealthy on those 4 days?
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The answer:
the EPA