instruction:
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.
question:
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"?
answer:
a diaphragm or a piston


question:
Passage: In February 1974, the British Prime Minister, Edward Heath, advised the Queen to call a general election in the middle of her tour of the Austronesian Pacific Rim, requiring her to fly back to Britain. The election resulted in a hung parliament; Heath's Conservatives were not the largest party, but could stay in office if they formed a coalition with the Liberals. Heath only resigned when discussions on forming a coalition foundered, after which the Queen asked the Leader of the Opposition, Labour's Harold Wilson, to form a government. Question: Where was Elizabeth when Heath advised that sh call for an election?
answer:
Austronesian Pacific Rim


question:
Passage: The Space Race can trace its origins to Germany, beginning in the 1930s and continuing during World War II when Nazi Germany researched and built operational ballistic missiles. Starting in the early 1930s, during the last stages of the Weimar Republic, German aerospace engineers experimented with liquid-fueled rockets, with the goal that one day they would be capable of reaching high altitudes and traversing long distances. The head of the German Army's Ballistics and Munitions Branch, Lieutenant Colonel Karl Emil Becker, gathered a small team of engineers that included Walter Dornberger and Leo Zanssen, to figure out how to use rockets as long-range artillery in order to get around the Treaty of Versailles' ban on research and development of long-range cannons. Wernher von Braun, a young engineering prodigy, was recruited by Becker and Dornberger to join their secret army program at Kummersdorf-West in 1932. Von Braun had dreams about conquering outer space with rockets, and did not initially see the military value in missile technology. Question: What were German aerospace engineers experimenting with in the 1930's?
answer:

liquid-fueled rockets