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.

Example Input: Passage: In the immediate aftermath of World War II, there occurred several armed incidents between Yugoslavia and the Western Allies. Following the war, Yugoslavia acquired the Italian territory of Istria as well as the cities of Zadar and Rijeka. Yugoslav leadership was looking to incorporate Trieste into the country as well, which was opposed by the Western Allies. This led to several armed incidents, notably attacks by Yugoslav fighter planes on US transport aircraft, causing bitter criticism from the west. From 1945 to 1948, at least four US aircraft were shot down.[better source needed] Stalin was opposed to these provocations, as he felt the USSR unready to face the West in open war so soon after the losses of World War II and at the time when US had operational nuclear weapons whereas USSR had yet to conduct its first test. In addition, Tito was openly supportive of the Communist side in the Greek Civil War, while Stalin kept his distance, having agreed with Churchill not to pursue Soviet interests there, although he did support the Greek communist struggle politically, as demonstrated in several assemblies of the UN Security Council. In 1948, motivated by the desire to create a strong independent economy, Tito modeled his economic development plan independently from Moscow, which resulted in a diplomatic escalation followed by a bitter exchange of letters in which Tito affirmed that Question: What Italian territory did Yugoslavia acquire after the war?
Example Output: Istria

Example Input: Passage: A elevator of this kind uses a vacuum on top of the cab and a valve on the top of the "shaft" to move the cab upwards and closes the valve in order to keep the cab at the same level. a diaphragm or a piston is used as a "brake" if there's a sudden increase in pressure avove the cab. however, to go down, it opens the valve so that the air can pressurize the top of the "shaft", allowing the cab to go down by its own weight. this also means that in case of a power failure, the cab will automatically go down. the "shaft" is made of acrilic, is always round, due to the shape of the vacuum pump turbine. in order to keep the air inside of the cab, rubber seals are used. due to technical limitations, these elevators have a low capacity. they usually allow 1-3 passengers and up to 525 lbs. Question: For sudden surges in pressure above the cab, what is used as a "brake"?
Example Output: a diaphragm or a piston

Example Input: Passage: The house which forms the architectural core of the palace was built for the first Duke of Buckingham and Normanby in 1703 to the design of William Winde. The style chosen was of a large, three-floored central block with two smaller flanking service wings. Buckingham House was eventually sold by Buckingham's descendant, Sir Charles Sheffield, in 1761 to George III for 21,000. Sheffield's leasehold on the mulberry garden site, the freehold of which was still owned by the royal family, was due to expire in 1774. Question: How much did George III pay for the house?
Example Output:
21,000