This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Q: Passage: On 30 September, Zhou Enlai warned the United States that China was prepared to intervene in Korea if the United States crossed the 38th parallel. Zhou attempted to advise North Korean commanders on how to conduct a general withdrawal by using the same tactics which had allowed Chinese communist forces to successfully escape Chiang Kai-shek's Encirclement Campaigns in the 1930s, but by some accounts North Korean commanders did not utilize these tactics effectively. Historian Bruce Cumings argues, however, the KPA's rapid withdrawal was strategic, with troops melting into the mountains from where they could launch guerrilla raids on the UN forces spread out on the coasts. Question: Who vowed to intervene if the US was to engage in conflict North of the 38th parallel?

A: China
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Q: Passage: Initially the change in strategy caught the RAF off-guard, and caused extensive damage and civilian casualties. Some 107,400 long tons (109,100 t) of shipping was damaged in the Thames Estuary and 1,600 civilians were casualties. Of this total around 400 were killed. The fighting in the air was more intense in daylight. Overall Loge had cost the Luftwaffe 41 aircraft; 14 bombers, 16 Messerschmitt Bf 109s, seven Messerschmitt Bf 110s and four reconnaissance aircraft. Fighter Command lost 23 fighters, with six pilots killed and another seven wounded. Another 247 bombers from Sperrle's Luftflotte 3 (Air Fleet 3) attacked that night. On 8 September, the Luftwaffe returned. This time 412 people were killed and 747 severely wounded. Question: How many German pilots were killed?

A: six
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Q: Passage: In the 11th century and the 12th century, the princes and their retinues, which were a mixture of Slavic and Scandinavian elites, dominated the society of Kievan Rus'. Leading soldiers and officials received income and land from the princes in return for their political and military services. Kievan society lacked the class institutions and autonomous towns that were typical of Western European feudalism. Nevertheless, urban merchants, artisans and labourers sometimes exercised political influence through a city assembly, the veche (council), which included all the adult males in the population. In some cases, the veche either made agreements with their rulers or expelled them and invited others to take their place. At the bottom of society was a stratum of slaves. More important was a class of tribute-paying peasants, who owed labour duty to the princes. The widespread personal serfdom characteristic of Western Europe did not exist in Kievan Rus'. Question: What was severely lacking in Kievan in the 12th century?

A:
class institutions and autonomous towns
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