Input: Read this: In recent decades, a series of inscribed graphs and pictures have been found at Neolithic sites in China, including Jiahu (c. 6500 BC), Dadiwan and Damaidi from the 6th millennium BC, and Banpo (5th millennium BC). Often these finds are accompanied by media reports that push back the purported beginnings of Chinese writing by thousands of years. However, because these marks occur singly, without any implied context, and are made crudely and simply, Qiu Xigui concluded that "we do not have any basis for stating that these constituted writing nor is there reason to conclude that they were ancestral to Shang dynasty Chinese characters." They do however demonstrate a history of sign use in the Yellow River valley during the Neolithic through to the Shang period.
Question: What has demonstrated a history of sign use in the Yellow River valley?

Output: Chinese characters


Input: Read this: Portugal’s national energy transmission company, Redes Energéticas Nacionais (REN), uses sophisticated modeling to predict weather, especially wind patterns, and computer programs to calculate energy from the various renewable-energy plants. Before the solar/wind revolution, Portugal had generated electricity from hydropower plants on its rivers for decades. New programs combine wind and water: wind-driven turbines pump water uphill at night, the most blustery period; then the water flows downhill by day, generating electricity, when consumer demand is highest. Portugal’s distribution system is also now a two-way street. Instead of just delivering electricity, it draws electricity from even the smallest generators, like rooftop solar panels. The government aggressively encouraged such contributions by setting a premium price for those who buy rooftop-generated solar electricity.
Question: What is the name of Portugal's national energy transmission company?

Output: Redes Energéticas Nacionais (REN)


Input: Read this: PlayStation 3 launched in North America with 14 titles, with another three being released before the end of 2006. After the first week of sales it was confirmed that Resistance: Fall of Man from Insomniac Games was the top-selling launch game in North America. The game was heavily praised by numerous video game websites, including GameSpot and IGN, both of whom awarded it their PlayStation 3 Game of the Year award for 2006. Some titles missed the launch window and were delayed until early 2007, such as The Elder Scrolls IV: Oblivion, F.E.A.R. and Sonic the Hedgehog. During the Japanese launch, Ridge Racer 7 was the top-selling game, while Mobile Suit Gundam: Crossfire also fared well in sales, both of which were offerings from Namco Bandai Games. PlayStation 3 launched in Europe with 24 titles, including ones that were not offered in North American and Japanese launches, such as Formula One Championship Edition, MotorStorm and Virtua Fighter 5. Resistance: Fall of Man and MotorStorm were the most successful titles of 2007, and both games subsequently received sequels in the form of Resistance 2 and MotorStorm: Pacific Rift.
Question: PS3 launched in South America with how many titles?

Output: unanswerable


Input: Read this: The verbs of most aspect pairs differ in one of two ways: by prefix or by suffix. In prefix pairs, the perfective verb has an added prefix—for example, the imperfective psát (to write, to be writing) compared with the perfective napsat (to write down, to finish writing). The most common prefixes are na-, o-, po-, s-, u-, vy-, z- and za-. In suffix pairs, a different infinitive ending is added to the perfective stem; for example, the perfective verbs koupit (to buy) and prodat (to sell) have the imperfective forms kupovat and prodávat. Imperfective verbs may undergo further morphology to make other imperfective verbs (iterative and frequentative forms), denoting repeated or regular action. The verb jít (to go) has the iterative form chodit (to go repeatedly) and the frequentative form chodívat (to go regularly).
Question: How many ways can a verb in an aspect pair differ?

Output:
two ways