Problem: By the 1860s the Kingdom of Prussia and the Austrian Empire were the two most powerful nations dominated by German-speaking elites. Both sought to expand their influence and territory. The Austrian Empire – like the Holy Roman Empire – was a multi-ethnic state, but German-speaking people there did not have an absolute numerical majority; the creation of the Austro-Hungarian Empire was one result of the growing nationalism of other ethnicities especially the Hungarians. Prussia under Otto von Bismarck would ride on the coat-tails of nationalism to unite all of modern-day Germany. The German Empire ("Second Reich") was created in 1871 following the proclamation of Wilhelm I as head of a union of German-speaking states, while disregarding millions of its non-German subjects who desired self-determination from German rule.
When was the German Empire created?
The answer is the following: 1871

Problem: With his third album, Graduation (2007), West moved away from the sound of his previous releases and towards a more atmospheric, rock-tinged, electronic-influenced soundscape. The musical evolution arose from him listening to music genres encompassing European Britpop and Euro-disco, American alternative and indie-rock, and his native Chicago house. Towards this end, West retracted much of the live instrumentation that characterized his previous album and replaced it with heavy, gothic synthesizers, distorted synth-chords, rave stabs, house beats, electro-disco rhythms, and a wide array of modulated electronic noises and digital audio-effects. In addition, West drew musical inspiration from arena rock bands such as The Rolling Stones, U2, and Led Zeppelin in terms of melody and chord progression.
Kanye drew inspiration from The Rolling Stones, U2, and Led Zeppelin in what ways?
The answer is the following: melody and chord progression

Problem: The Republic of the Congo also has large untapped base metal, gold, iron and phosphate deposits. The country is a member of the Organization for the Harmonization of Business Law in Africa (OHADA). The Congolese government signed an agreement in 2009 to lease 200,000 hectares of land to South African farmers to reduce its dependence on imports.
How much land did the Congolese government agree to lease to South Africans in 2009?
The answer is the following: 200,000 hectares

Problem: The role of the gas is to prevent evaporation of the filament, without introducing significant heat losses. For these properties, chemical inertness and high atomic or molecular weight is desirable. The presence of gas molecules knocks the liberated tungsten atoms back to the filament, reducing its evaporation and allowing it to be operated at higher temperature without reducing its life (or, for operating at the same temperature, prolongs the filament life). It however introduces heat losses (and therefore efficiency loss) from the filament, by heat conduction and heat convection.
What is the purpose of the gas in a light bulb?
The answer is the following:
to prevent evaporation of the filament, without introducing significant heat losses