Problem: Railway electrification system:

Electric railways use electric locomotives to haul passengers or freight in separate cars or electric multiple units, passenger cars with their own motors. Electricity is typically generated in large and relatively efficient generating stations, transmitted to the railway network and distributed to the trains. Some electric railways have their own dedicated generating stations and transmission lines but most purchase power from an electric utility. The railway usually provides its own distribution lines, switches and transformers.

What entity provides distribution lines, switches and transformers?
---
A: railway


Problem: The most extreme forms of Cubism were not those practiced by Picasso and Braque, who resisted total abstraction. Other Cubists, by contrast, especially František Kupka, and those considered Orphists by Apollinaire (Delaunay, Léger, Picabia and Duchamp), accepted abstraction by removing visible subject matter entirely. Kupka’s two entries at the 1912 Salon d'Automne, Amorpha-Fugue à deux couleurs and Amorpha chromatique chaude, were highly abstract (or nonrepresentational) and metaphysical in orientation. Both Duchamp in 1912 and Picabia from 1912 to 1914 developed an expressive and allusive abstraction dedicated to complex emotional and sexual themes. Beginning in 1912 Delaunay painted a series of paintings entitled Simultaneous Windows, followed by a series entitled Formes Circulaires, in which he combined planar structures with bright prismatic hues; based on the optical characteristics of juxtaposed colors his departure from reality in the depiction of imagery was quasi-complete. In 1913–14 Léger produced a series entitled Contrasts of Forms, giving a similar stress to color, line and form. His Cubism, despite its abstract qualities, was associated with themes of mechanization and modern life. Apollinaire supported these early developments of abstract Cubism in Les Peintres cubistes (1913), writing of a new "pure" painting in which the subject was vacated. But in spite of his use of the term Orphism these works were so different that they defy attempts to place them in a single category.
 What were Kupka's three entries at the Salon d'Automne?
---
Answer: unanswerable


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Throughout the 14th century, French kings sought to expand their influence at the expense of the territorial holdings of the nobility. They ran into difficulties when attempting to confiscate the holdings of the English kings in southern France, leading to the Hundred Years' War, waged from 1337 to 1453. Early in the war the English under Edward III (r. 1327–77) and his son Edward, the Black Prince (d. 1376),[AF] won the battles of Crécy and Poitiers, captured the city of Calais, and won control of much of France.[AG] The resulting stresses almost caused the disintegration of the French kingdom during the early years of the war. In the early 15th century, France again came close to dissolving, but in the late 1420s the military successes of Joan of Arc (d. 1431) led to the victory of the French and the capture of the last English possessions in southern France in 1453. The price was high, as the population of France at the end of the Wars was likely half what it had been at the start of the conflict. Conversely, the Wars had a positive effect on English national identity, doing much to fuse the various local identities into a national English ideal. The conflict with France also helped create a national culture in England separate from French culture, which had previously been the dominant influence. The dominance of the English longbow began during early stages of the Hundred Years' War, and cannon appeared on the battlefield at Crécy in 1346.
What was the nickname of Edward III's son Edward?
A: the Black Prince


Context and question: For over 200 years, Russia had been expanding southwards across the sparsely populated "Wild Fields" toward the warm water ports of the Black Sea that did not freeze over like the handful of other ports available in the north. The goal was to promote year-round trade and a year-round navy.:11 Pursuit of this goal brought the emerging Russian state into conflict with the Ukrainian Cossacks and then with the Tatars of the Crimean Khanate and Circassians. When Russia conquered these groups and gained possession of southern Ukraine, known as New Russia during Russian imperial times, the Ottoman Empire lost its buffer zone against Russian expansion, and Russia and the Ottoman Empire fell into direct conflict. The conflict with the Ottoman Empire also presented a religious issue of importance, as Russia saw itself as the protector of Orthodox Christians, many of whom lived under Ottoman control and were treated as second-class citizens.(ch 1)
Why did Russia move towards the warmer ports of the Black Sea?
Answer: to promote year-round trade and a year-round navy


Question: In recent years there was a high demand for massively distributed databases with high partition tolerance but according to the CAP theorem it is impossible for a distributed system to simultaneously provide consistency, availability and partition tolerance guarantees. A distributed system can satisfy any two of these guarantees at the same time, but not all three. For that reason many NoSQL databases are using what is called eventual consistency to provide both availability and partition tolerance guarantees with a reduced level of data consistency.
Is there an answer to this question: What can satisfy all guarantees at the same time?

Answer: unanswerable


Problem: London:

Herds of red and fallow deer also roam freely within much of Richmond and Bushy Park. A cull takes place each November and February to ensure numbers can be sustained. Epping Forest is also known for its fallow deer, which can frequently be seen in herds to the north of the Forest. A rare population of melanistic, black fallow deer is also maintained at the Deer Sanctuary near Theydon Bois. Muntjac deer, which escaped from deer parks at the turn of the twentieth century, are also found in the forest. While Londoners are accustomed to wildlife such as birds and foxes sharing the city, more recently urban deer have started becoming a regular feature, and whole herds of fallow and white-tailed deer come into residential areas at night to take advantage of the London's green spaces.

When do culls to ensure sustainability of London's deer population occur?
---
A:
each November and February