Use a disfluent question or a proper question and find the answer to the question based on the given context or return None if an answer can't be found. A disfluent question is a question that has some interruptions in it while framing. A proper question is the correct form of the question without any disfluency.
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Question: proper question: Who has a classification system for all North American companies? 
 disfluent question: Who has a subsector no the classification system for all North American companies? 
 context: The Standard Industrial Classification and the newer North American Industry Classification System have a classification system for companies that perform or otherwise engage in construction. To recognize the differences of companies in this sector, it is divided into three subsectors: building construction, heavy and civil engineering construction, and specialty trade contractors. There are also categories for construction service firms (e.g., engineering, architecture) and construction managers (firms engaged in managing construction projects without assuming direct financial responsibility for completion of the construction project).

Answer: None


Question: proper question: What was the population density in 1970? 
 disfluent question: What racial group  no What was the population density in 1970? 
 context: The 2010 United States Census reported that Fresno had a population of 494,665. The population density was 4,404.5 people per square mile (1,700.6/km²). The racial makeup of Fresno was 245,306 (49.6%) White, 40,960 (8.3%) African American, 8,525 (1.7%) Native American, 62,528 (12.6%) Asian (3.6% Hmong, 1.7% Indian, 1.2% Filipino, 1.2% Laotian, 1.0% Thai, 0.8% Cambodian, 0.7% Chinese, 0.5% Japanese, 0.4% Vietnamese, 0.2% Korean), 849 (0.2%) Pacific Islander, 111,984 (22.6%) from other races, and 24,513 (5.0%) from two or more races. Hispanic or Latino of any race were 232,055 persons (46.9%). Among the Hispanic population, 42.7% of the total population are Mexican, 0.4% Salvadoran, and 0.4% Puerto Rican. Non-Hispanic Whites were 30.0% of the population in 2010, down from 72.6% in 1970.

Answer: None


Question: proper question: What evidence did Plato use to explain life-forms? 
 disfluent question: What evidence did Louis Agassiz or rather Plato use to explain life-forms? 
 context: In 1846, the natural history lectures of Louis Agassiz were acclaimed both in New York and on the campus at Harvard College. Agassiz's approach was distinctly idealist and posited Americans' participation in the Divine Nature and the possibility of understanding intellectual existences. Agassiz's perspective on science combined observation with intuition and the assumption that a person can grasp the divine plan in all phenomena. When it came to explaining life-forms, Agassiz resorted to matters of shape based on a presumed archetype for his evidence. This dual view of knowledge was in concert with the teachings of Common Sense Realism derived from Scottish philosophers Thomas Reid and Dugald Stewart, whose works were part of the Harvard curriculum at the time. The popularity of Agassiz's efforts to soar with Plato probably also derived from other writings to which Harvard students were exposed, including Platonic treatises by Ralph Cudworth, John Norrisand, in a Romantic vein, Samuel Coleridge. The library records at Harvard reveal that the writings of Plato and his early modern and Romantic followers were almost as regularly read during the 19th century as those of the official philosophy of the more empirical and more deistic Scottish school.

Answer:
None