Problem: Gothic architecture:

In 1663 at the Archbishop of Canterbury's residence, Lambeth Palace, a Gothic hammerbeam roof was built to replace that destroyed when the building was sacked during the English Civil War. Also in the late 17th century, some discrete Gothic details appeared on new construction at Oxford University and Cambridge University, notably on Tom Tower at Christ Church, Oxford, by Christopher Wren. It is not easy to decide whether these instances were Gothic survival or early appearances of Gothic revival.

Who avoided Gothic details in construction of Tom Tower, Oxford?
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A: unanswerable

Problem: Gramophone record:

By about 1910,[note 1] bound collections of empty sleeves with a paperboard or leather cover, similar to a photograph album, were sold as record albums that customers could use to store their records (the term "record album" was printed on some covers). These albums came in both 10-inch and 12-inch sizes. The covers of these bound books were wider and taller than the records inside, allowing the record album to be placed on a shelf upright, like a book, suspending the fragile records above the shelf and protecting them.

What sizes were record album covers available in?
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A: 10-inch and 12-inch sizes

Problem: Gregorian calendar:

The Gregorian calendar improves the approximation made by the Julian calendar by skipping three Julian leap days in every 400 years, giving an average year of 365.2425 mean solar days long. This approximation has an error of about one day per 3,300 years with respect to the mean tropical year. However, because of the precession of the equinoxes, the error with respect to the vernal equinox (which occurs, on average, 365.24237 days apart near 2000) is 1 day every 7,700 years, assuming a constant time interval between vernal equinoxes, which is not true. By any criterion, the Gregorian calendar is substantially more accurate than the 1 day in 128 years error of the Julian calendar (average year 365.25 days).

How many days must be skipped to align the calendar with mean solar days in a year?
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A: three Julian leap days

Problem: Josip Broz Tito:

In the immediate aftermath of World War II, there occurred several armed incidents between Yugoslavia and the Western Allies. Following the war, Yugoslavia acquired the Italian territory of Istria as well as the cities of Zadar and Rijeka. Yugoslav leadership was looking to incorporate Trieste into the country as well, which was opposed by the Western Allies. This led to several armed incidents, notably attacks by Yugoslav fighter planes on US transport aircraft, causing bitter criticism from the west. From 1945 to 1948, at least four US aircraft were shot down.[better source needed] Stalin was opposed to these provocations, as he felt the USSR unready to face the West in open war so soon after the losses of World War II and at the time when US had operational nuclear weapons whereas USSR had yet to conduct its first test. In addition, Tito was openly supportive of the Communist side in the Greek Civil War, while Stalin kept his distance, having agreed with Churchill not to pursue Soviet interests there, although he did support the Greek communist struggle politically, as demonstrated in several assemblies of the UN Security Council. In 1948, motivated by the desire to create a strong independent economy, Tito modeled his economic development plan independently from Moscow, which resulted in a diplomatic escalation followed by a bitter exchange of letters in which Tito affirmed that

At least how many American aircraft were shot down between 1945 and 1948?
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A:
four