Problem: At the end of the first decade of the 21st century, downtown Tucson underwent a revitalization effort by city planners and the business community. The primary project was Rio Nuevo, a large retail and community center that has been stalled in planning for more than ten years. Downtown is generally regarded as the area bordered by 17th Street to the south, I-10 to the west, and 6th Street to the north, and Toole Avenue and the Union Pacific (formerly Southern Pacific) railroad tracks, site of the historic train depot and "Locomotive #1673", built in 1900. Downtown is divided into the Presidio District, the Barrio Viejo, and the Congress Street Arts and Entertainment District. Some authorities include the 4th Avenue shopping district, which is set just northeast of the rest of downtown and connected by an underpass beneath the UPRR tracks.
What is the southern edge of Tucson's downtown?
The answer is the following: 17th Street

Problem: The land within the borders of current Portugal has been continuously settled and fought over since prehistoric times. The Celts and the Romans were followed by the Visigothic and the Suebi Germanic peoples, who were themselves later invaded by the Moors. These Muslim peoples were eventually expelled during the Christian Reconquista of the peninsula. By 1139, Portugal had established itself as a kingdom independent from León. In the 15th and 16th centuries, as the result of pioneering the Age of Discovery, Portugal expanded Western influence and established the first global empire, becoming one of the world's major economic, political and military powers.
By what year had Portugal established itself as an independent kingdom?
The answer is the following: 1139

Problem: The decision to change strategy is sometimes claimed as a major mistake by the Oberkommando der Luftwaffe (OKL). It is argued that persisting with attacks on RAF airfields might have won air superiority for the Luftwaffe. Others argue that the Luftwaffe made little impression on Fighter Command in the last week of August and first week of September and that the shift in strategy was not decisive. It has also been argued that it was doubtful the Luftwaffe could have won air superiority before the "weather window" began to deteriorate in October. It was also possible, if RAF losses became severe, that they could pull out to the north, wait for the German invasion, then redeploy southward again. Other historians argue that the outcome of the air battle was irrelevant; the massive numerical superiority of British naval forces and the inherent weakness of the Kriegsmarine would have made the projected German invasion, Unternehmen Seelöwe (Operation Sea Lion), a disaster with or without German air superiority.
What month would the weather window begin to decline?
The answer is the following: October

Problem: Soviet Premier Nikita Khrushchev announced that a "spy-plane" had been shot down but intentionally made no reference to the pilot. As a result, the Eisenhower Administration, thinking the pilot had died in the crash, authorized the release of a cover story claiming that the plane was a "weather research aircraft" which had unintentionally strayed into Soviet airspace after the pilot had radioed "difficulties with his oxygen equipment" while flying over Turkey. The Soviets put Captain Powers on trial and displayed parts of the U-2, which had been recovered almost fully intact.
What did Khrushchev refer to the U-2 as?
The answer is the following:
spy-plane