Problem: Illustrated humour periodicals were popular in 19th-century Britain, the earliest of which was the short-lived The Glasgow Looking Glass in 1825. The most popular was Punch, which popularized the term cartoon for its humorous caricatures. On occasion the cartoons in these magazines appeared in sequences; the character Ally Sloper featured in the earliest serialized comic strip when the character began to feature in its own weekly magazine in 1884.
Which comic character was the first to appear in a weekly magazine?
The answer is the following: Ally Sloper

Problem: The production for sulfidic zinc ores produces large amounts of sulfur dioxide and cadmium vapor. Smelter slag and other residues of process also contain significant amounts of heavy metals. About 1.1 million tonnes of metallic zinc and 130 thousand tonnes of lead were mined and smelted in the Belgian towns of La Calamine and Plombieres between 1806 and 1882. The dumps of the past mining operations leach significant amounts of zinc and cadmium, and, as a result, the sediments of the Geul River contain significant amounts of heavy metals. About two thousand years ago emissions of zinc from mining and smelting totaled 10 thousand tonnes a year. After increasing 10-fold from 1850, zinc emissions peaked at 3.4 million tonnes per year in the 1980s and declined to 2.7 million tonnes in the 1990s, although a 2005 study of the Arctic troposphere found that the concentrations there did not reflect the decline. Anthropogenic and natural emissions occur at a ratio of 20 to 1.
Why does the Geul River contain heavy metals in a significant amount?
The answer is the following: mining operations leach significant amounts of zinc and cadmium

Problem: Chopin arrived in Paris in late September 1831; he would never return to Poland, thus becoming one of many expatriates of the Polish Great Emigration. In France he used the French versions of his given names, and after receiving French citizenship in 1835, he travelled on a French passport. However, Chopin remained close to his fellow Poles in exile as friends and confidants and he never felt fully comfortable speaking French. Chopin's biographer Adam Zamoyski writes that he never considered himself to be French, despite his father's French origins, and always saw himself as a Pole.
In what year did Chopin become a French citizen?
The answer is the following: 1835

Problem: Excluding the outlying parks of Bois de Boulogne and Bois de Vincennes, Paris covers an oval measuring about 87 km2 (34 sq mi) in area, enclosed by the 35 km (22 mi) ring road, the Boulevard Peripherique. The city's last major annexation of outlying territories in 1860 not only gave it its modern form but also created the 20 clockwise-spiralling arrondissements (municipal boroughs). From the 1860 area of 78 km2 (30 sq mi), the city limits were expanded marginally to 86.9 km2 (33.6 sq mi) in the 1920s. In 1929, the Bois de Boulogne and Bois de Vincennes forest parks were officially annexed to the city, bringing its area to about 105 km2 (41 sq mi). The metropolitan area of the city is 2,300 km2 (890 sq mi).
In what year were Bois de Boulogne and Bois de Vincennes annexed?
The answer is the following:
1929