Question: Stage lifts and orchestra lifts are specialized elevators, typically powered by hydraulics, that are used to raise and lower entire sections of a theater stage. For example, Radio City Music Hall has four such elevators: an orchestra lift that covers a large area of the stage, and three smaller lifts near the rear of the stage. In this case, the orchestra lift is powerful enough to raise an entire orchestra, or an entire cast of performers (including live elephants) up to stage level from below. There's a barrel on the background of the image of the left which can be used as a scale to represent the size of the mechanism
Is there an answer to this question: How many hydraulic elevators are there at Radio City Music Hall?

Answer: four

Question: With the defeat of the First Army, Prince Frederick Charles ordered a massed artillery attack against Canrobert's position at St. Privat to prevent the Guards attack from failing too. At 19:00 the 3rd Division of Fransecky's II Corps of the Second Army advanced across Ravine while the XII Corps cleared out the nearby town of Roncourt and with the survivors of the 1st Guards Infantry Division launched a fresh attack against the ruins of St. Privat. At 20:00, the arrival of the Prussian 4th Infantry Division of the II Corps and with the Prussian right flank on Mance Ravine, the line stabilised. By then, the Prussians of the 1st Guards Infantry Division and the XII and II Corps captured St. Privat forcing the decimated French forces to withdraw. With the Prussians exhausted from the fighting, the French were now able to mount a counter-attack. General Bourbaki, however, refused to commit the reserves of the French Old Guard to the battle because, by that time, he considered the overall situation a 'defeat'. By 22:00, firing largely died down across the battlefield for the night. The next morning, the French Army of the Rhine, rather than resume the battle with an attack of its own against the battle-weary German armies, retreated to Metz where they were besieged and forced to surrender two months later.
Is there an answer to this question: Which army was forced to retreat to Metz and surrender two months later?

Answer: French Army of the Rhine

Question: The Sumerians developed a complex system of metrology c. 4000 BC. This advanced metrology resulted in the creation of arithmetic, geometry, and algebra. From c. 2600 BC onwards, the Sumerians wrote multiplication tables on clay tablets and dealt with geometrical exercises and division problems. The earliest traces of the Babylonian numerals also date back to this period. The period c. 2700 2300 BC saw the first appearance of the abacus, and a table of successive columns which delimited the successive orders of magnitude of their sexagesimal number system. The Sumerians were the first to use a place value numeral system. There is also anecdotal evidence the Sumerians may have used a type of slide rule in astronomical calculations. They were the first to find the area of a triangle and the volume of a cube.
Is there an answer to this question: Where did the Sumerians put their multiplication tables?

Answer: on clay tablets

Question: Czech, the official language of the Czech Republic (a member of the European Union since 2004), is one of the EU's official languages and the 2012 Eurobarometer survey found that Czech was the foreign language most often used in Slovakia. Economist Jonathan van Parys collected data on language knowledge in Europe for the 2012 European Day of Languages. The five countries with the greatest use of Czech were the Czech Republic (98.77 percent), Slovakia (24.86 percent), Portugal (1.93 percent), Poland (0.98 percent) and Germany (0.47 percent).
Is there an answer to this question: How long has Slovakia been a member of the EU?

Answer:
unanswerable