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.
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Question: Passage: Indian astronomer and mathematician Aryabhata (476-550), in his Aryabhatiya (499) introduced a number of trigonometric functions (including sine, versine, cosine and inverse sine), trigonometric tables, and techniques and algorithms of algebra. In 628 AD, Brahmagupta suggested that gravity was a force of attraction. He also lucidly explained the use of zero as both a placeholder and a decimal digit, along with the Hindu-Arabic numeral system now used universally throughout the world. Arabic translations of the two astronomers' texts were soon available in the Islamic world, introducing what would become Arabic numerals to the Islamic World by the 9th century. During the 14th–16th centuries, the Kerala school of astronomy and mathematics made significant advances in astronomy and especially mathematics, including fields such as trigonometry and analysis. In particular, Madhava of Sangamagrama is considered the "founder of mathematical analysis". Question: What did Brahmagupta use the number zero for?

Answer: a placeholder and a decimal digit


Question: Passage: Mach argued that, in effect, the water experiment in an otherwise empty universe would remain flat. But if another object were introduced into this universe, perhaps a distant star, there would now be something relative to which the bucket could be seen as rotating. The water inside the bucket could possibly have a slight curve. To account for the curve that we observe, an increase in the number of objects in the universe also increases the curvature in the water. Mach argued that the momentum of an object, whether angular or linear, exists as a result of the sum of the effects of other objects in the universe (Mach's Principle). Question: Mach argued that the momentum of an object exists as a result of the sum of the effects of what?

Answer: effects of other objects in the universe


Question: Passage: By 1885, a new summer retreat was contemplated. That summer, the Bells had a vacation on Cape Breton Island in Nova Scotia, spending time at the small village of Baddeck. Returning in 1886, Bell started building an estate on a point across from Baddeck, overlooking Bras d'Or Lake. By 1889, a large house, christened The Lodge was completed and two years later, a larger complex of buildings, including a new laboratory, were begun that the Bells would name Beinn Bhreagh (Gaelic: beautiful mountain) after Bell's ancestral Scottish highlands.[N 21] Bell also built the Bell Boatyard on the estate, employing up to 40 people building experimental craft as well as wartime lifeboats and workboats for the Royal Canadian Navy and pleasure craft for the Bell family. An enthusiastic boater, Bell and his family sailed or rowed a long series of vessels on Bras d'Or Lake, ordering additional vessels from the H.W. Embree and Sons boatyard in Port Hawkesbury, Nova Scotia. In his final, and some of his most productive years, Bell split his residency between Washington, D.C., where he and his family initially resided for most of the year, and at Beinn Bhreagh where they spent increasing amounts of time. Question: What did the Bells call the house completed in 1889?

Answer:
The Lodge