Problem: Incandescent light bulb:

With the help of Charles Stearn, an expert on vacuum pumps, in 1878, Swan developed a method of processing that avoided the early bulb blackening. This received a British Patent in 1880.[dubious discuss] On 18 December 1878, a lamp using a slender carbon rod was shown at a meeting of the Newcastle Chemical Society, and Swan gave a working demonstration at their meeting on 17 January 1879. It was also shown to 700 who attended a meeting of the Literary and Philosophical Society of Newcastle upon Tyne on 3 February 1879. These lamps used a carbon rod from an arc lamp rather than a slender filament. Thus they had low resistance and required very large conductors to supply the necessary current, so they were not commercially practical, although they did furnish a demonstration of the possibilities of incandescent lighting with relatively high vacuum, a carbon conductor, and platinum lead-in wires. Besides requiring too much current for a central station electric system to be practical, they had a very short lifetime. Swan turned his attention to producing a better carbon filament and the means of attaching its ends. He devised a method of treating cotton to produce 'parchmentised thread' and obtained British Patent 4933 in 1880. From this year he began installing light bulbs in homes and landmarks in England. His house was the first in the world to be lit by a lightbulb and also the first house in the world to be lit by hydroelectric power. In 1878 the home of Lord Armstrong at Cragside was also among the first houses to be lit by electricity. In the early 1880s he had started his company. In 1881, the Savoy Theatre in the City of Westminster, London was lit by Swan incandescent lightbulbs, which was the first theatre, and the first public building in the world, to be lit entirely by electricity.

Why was Swan's first lamp commercially viable?
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A: unanswerable

Problem: ^Note 5: The North Carolina Constitution of 1776 disestablished the Anglican church, but until 1835 the NC Constitution allowed only Protestants to hold public office. From 1835-1876 it allowed only Christians (including Catholics) to hold public office. Article VI, Section 8 of the current NC Constitution forbids only atheists from holding public office. Such clauses were held by the United States Supreme Court to be unenforceable in the 1961 case of Torcaso v. Watkins, when the court ruled unanimously that such clauses constituted a religious test incompatible with First and Fourteenth Amendment protections.
When did the U.S. Supreme Court rule clauses allow people to hold public office based on their religion was unenforceable?
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Answer: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Thus, Buckingham Palace is a symbol and home of the British monarchy, an art gallery and a tourist attraction. Behind the gilded railings and gates which were completed by the Bromsgrove Guild in 1911 and Webb's famous facade, which has been described in a book published by the Royal Collection as looking "like everybody's idea of a palace", is not only a weekday home of the Queen and Prince Philip but also the London residence of the Duke of York and the Earl and Countess of Wessex. The palace also houses the offices of the Queen, Prince Philip, Duke of York, Earl and Countess of Wessex, Princess Royal, and Princess Alexandra, and is the workplace of more than 800 people.
Who completed the palaces gilded railing and gates?
A: Bromsgrove Guild

Context and question: Tucson (/tusn/ /tusn/) is a city and the county seat of Pima County, Arizona, United States, and home to the University of Arizona. The 2010 United States Census put the population at 520,116, while the 2013 estimated population of the entire Tucson metropolitan statistical area (MSA) was 996,544. The Tucson MSA forms part of the larger Tucson-Nogales combined statistical area (CSA), with a total population of 980,263 as of the 2010 Census. Tucson is the second-largest populated city in Arizona behind Phoenix, both of which anchor the Arizona Sun Corridor. The city is located 108 miles (174 km) southeast of Phoenix and 60 mi (97 km) north of the U.S.-Mexico border. Tucson is the 33rd largest city and the 59th largest metropolitan area in the United States. Roughly 150 Tucson companies are involved in the design and manufacture of optics and optoelectronics systems, earning Tucson the nickname Optics Valley.
What is the largest populated city in Arizona?
Answer: Phoenix

Question: After the end of hostilities, a period of growth and expansion started for the city. In 1853 a stagecoach bus line was established joining Montevideo with the newly formed settlement of Union and the first natural gas street lights were inaugurated.[citation needed] From 1854 to 1861 the first public sanitation facilities were constructed. In 1856 the Teatro Solis was inaugurated, 15 years after the beginning of its construction. By Decree, on December 1861 the areas of Aguada and Cordon were incorporated to the growing Ciudad Nueva (New City). In 1866, an underwater telegraph line connected the city with Buenos Aires. The statue of Peace, La Paz, was erected on a column in Plaza Cagancha and the building of the Postal Service as well as the bridge of Paso Molino were inaugurated in 1867.
Is there an answer to this question: What year was a stagecoach bus line established in Montevideo?

Answer: 1853

The number of species invasions has been on the rise at least since the beginning of the 1900s. Species are increasingly being moved by humans (on purpose and accidentally). In some cases the invaders are causing drastic changes and damage to their new habitats (e.g.: zebra mussels and the emerald ash borer in the Great Lakes region and the lion fish along the North American Atlantic coast). Some evidence suggests that invasive species are competitive in their new habitats because they are subject to less pathogen disturbance. Others report confounding evidence that occasionally suggest that species-rich communities harbor many native and exotic species simultaneously while some say that diverse ecosystems are more resilient and resist invasive plants and animals. An important question is, "do invasive species cause extinctions?" Many studies cite effects of invasive species on natives, but not extinctions. Invasive species seem to increase local (i.e.: alpha diversity) diversity, which decreases turnover of diversity (i.e.: beta diversity). Overall gamma diversity may be lowered because species are going extinct because of other causes, but even some of the most insidious invaders (e.g.: Dutch elm disease, emerald ash borer, chestnut blight in North America) have not caused their host species to become extinct. Extirpation, population decline, and homogenization of regional biodiversity are much more common. Human activities have frequently been the cause of invasive species circumventing their barriers, by introducing them for food and other purposes. Human activities therefore allow species to migrate to new areas (and thus become invasive) occurred on time scales much shorter than historically have been required for a species to extend its range.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What invaders are causing changes in the Great Lakes region?
Ah, so..
zebra mussels and the emerald ash borer