Problem: Dell:

In the early 1990s, Dell sold its products through Best Buy, Costco and Sam's Club stores in the United States. Dell stopped this practice in 1994, citing low profit-margins on the business, exclusively distributing through a direct-sales model for the next decade. In 2003, Dell briefly sold products in Sears stores in the U.S. In 2007, Dell started shipping its products to major retailers in the U.S. once again, starting with Sam's Club and Wal-Mart. Staples, the largest office-supply retailer in the U.S., and Best Buy, the largest electronics retailer in the U.S., became Dell retail partners later that same year.

Who is the smallest electronics retailer in the US?
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A: unanswerable

Problem: Diarrhea:

Dietary deficiencies in developing countries can be combated by promoting better eating practices. Supplementation with vitamin A and/or zinc. Zinc supplementation proved successful showing a significant decrease in the incidence of diarrheal disease compared to a control group. The majority of the literature suggests that vitamin A supplementation is advantageous in reducing disease incidence. Development of a supplementation strategy should take into consideration the fact that vitamin A supplementation was less effective in reducing diarrhea incidence when compared to vitamin A and zinc supplementation, and that the latter strategy was estimated to be significantly more cost effective.

What actions help combat diarrhea?
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A: unanswerable

Problem: Education:

While considered "alternative" today, most alternative systems have existed since ancient times. After the public school system was widely developed beginning in the 19th century, some parents found reasons to be discontented with the new system. Alternative education developed in part as a reaction to perceived limitations and failings of traditional education. A broad range of educational approaches emerged, including alternative schools, self learning, homeschooling and unschooling. Example alternative schools include Montessori schools, Waldorf schools (or Steiner schools), Friends schools, Sands School, Summerhill School, The Peepal Grove School, Sudbury Valley School, Krishnamurti schools, and open classroom schools. Charter schools are another example of alternative education, which have in the recent years grown in numbers in the US and gained greater importance in its public education system.

What hasn't gained importance in public education?
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A: unanswerable

Problem: Philadelphia:

The Philadelphia dialect, which is spread throughout the Delaware Valley and South Jersey, is part of Mid-Atlantic American English, and as such it is identical in many ways to the Baltimore dialect. Unlike the Baltimore dialect, however, the Philadelphia accent also shares many similarities with the New York accent. Thanks to over a century of linguistics data collected by researchers at the University of Pennsylvania, the Philadelphia dialect under sociolinguist William Labov has been one of the best-studied forms of American English.[f]

Who studies the accent at the University of Pennsylvania?
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A:
William Labov