In this task, you will be presented with a context passage, a question about that paragraph, and a possible answer to that question. The task is to check the validity of the answer. Answer with "Yes" or "No".

[EX Q]: A flood occurs when a river overflows its banks. This might happen because of heavy rains. Floodplains In very flat regions, flood water may spread out on the surface of the land. It then slows down and drops its sediment. If a river floods often, a floodplain develops. A floodplain is an area where a thick layer of rich soil is left behind as the floodwater recedes. Thats why floodplains are usually good places for growing plants. They are very flat areas and they have very rich soils. The Nile River valley is a great example of a floodplain. Each year, the Nile River rises over its banks. This floodwater carries a lot of sediment. This sediment has been eroded off areas of land from upstream. This sediment is dropped as the water slows down after spreading across the land. What is left behind is a very rich soil. Thats why crops can be raised in the middle of a sandy desert. Natural Levees A flooding river often forms natural levees along its banks. A levee is a raised strip of sediments deposited close to the waters edge. <sep>Where does the sediment in a flooding river come from, and where does it eventually come to rest?<sep>It comes from eroded rock and land and rests when the water receeds
[EX A]: Yes

[EX Q]: The Golden Heian Era: The geomancers in 794 decided that Heian-kyo (modern Kyoto) would be an auspicious site for the imperial family. It was indeeduntil 1869. Grants of tax-free land over the years had been made to Buddhist temples and members of the court aristocracy. The most powerful families thus carved out for themselves whole regions that were to become the fiefdoms of Japanese feudalism. By the end of the eighth century the clans had created a hierarchy of shiki, or rights, from the highest to the lowest ranks of society. The aristocrat or court patron lent his prestige to a powerful provincial proprietor, who employed a competent estate-manager to oversee smallholders, who in turn worked their farms with dependent laborers. This elaborate structure of interdependent rights and obligations was to serve Japanese society right into the 20th century. Meanwhile, Heian court life blossomed in an effusion of aesthetic expression. Princes and princesses judged the merits of birds, insects, flowers, roots, or seashells. Literary party games held in ornate palace gardens required each guest to compose a small poem as his wine cup floated toward him along a miniature winding channel of water. Expeditions were organized to the best viewing points for the first spring cherry blossoms, and special pavilions were built to watch the rising of the full moon. Every gesture, from the most banal opening of an umbrella to the sublimest act of lovemaking, had its appropriate ceremonial. Conversation often took the form of elegant exchanges of improvised verse. The changing role of Chinese culture in Japanese life was epitomized in the language itself. In the absence of an indigenous alphabet, Japanese scholars had with the greatest difficulty tried to adapt the complex ideograms of monosyllabic Chinese to the essentially polysyllabic Japanese. Thus developed the katakana system used as a vehicle for writing Buddhist names and concepts. After rival Fujiwara factions had been struggling for years to gain control of the imperial throne, they turned to the Taira and Minamoto armies in 1156 to wage the four-year war that heralded the end of the golden age of the Heian court. The Taira, controlling the region along the Inland Sea, defeated the Minamoto armies based in the Kanto province east of the capital. <sep>What time period was Heian-kyo used as a site for the imperial family?<sep>From 794 to 1869
[EX A]: Yes

[EX Q]: Alexander's death was so sudden that when reports of his death reached Greece, they were not immediately believed. Alexander had no obvious or legitimate heir, his son Alexander IV by Roxane being born after Alexander's death. According to Diodorus, Alexander's companions asked him on his deathbed to whom he bequeathed his kingdom; his laconic reply was "toi kratistoi"--"to the strongest". Arrian and Plutarch claimed that Alexander was speechless by this point, implying that this was an apocryphal story. Diodorus, Curtius and Justin offered the more plausible story that Alexander passed his signet ring to Perdiccas, a bodyguard and leader of the companion cavalry, in front of witnesses, thereby nominating him. Perdiccas initially did not claim power, instead suggesting that Roxane's baby would be king, if male; with himself, Craterus, Leonnatus, and Antipater as guardians. However, the infantry, under the command of Meleager, rejected this arrangement since they had been excluded from the discussion. Instead, they supported Alexander's half-brother Philip Arrhidaeus. Eventually, the two sides reconciled, and after the birth of Alexander IV, he and Philip III were appointed joint kings, albeit in name only. Dissension and rivalry soon afflicted the Macedonians, however. The satrapies handed out by Perdiccas at the Partition of Babylon became power bases each general used to bid for power. After the assassination of Perdiccas in 321 BC, Macedonian unity collapsed, and 40 years of war between "The Successors" (Diadochi) ensued before the Hellenistic world settled into four stable power blocks: Ptolemaic Egypt, Selucid Mesopotamia and Central Asia, Attalid Anatolia, and Antigonid Macedon. In the process, both Alexander IV and Philip III were murdered. <sep>What leads to both Alexander IV and Philip III getting murdered?<sep>The birth of Alexander IV
[EX A]:
No