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: In the mid-1950s, Frank Burnet, inspired by a suggestion made by Niels Jerne, formulated the clonal selection theory (CST) of immunity. On the basis of CST, Burnet developed a theory of how an immune response is triggered according to the self/nonself distinction: "self" constituents (constituents of the body) do not trigger destructive immune responses, while "nonself" entities (e.g., pathogens, an allograft) trigger a destructive immune response. The theory was later modified to reflect new discoveries regarding histocompatibility or the complex "two-signal" activation of T cells. The self/nonself theory of immunity and the self/nonself vocabulary have been criticized, but remain very influential. Question: What property of T cells caused modification of CST?

Answer: the complex "two-signal" activation


Question: Passage: Pope Sixtus V limited the number of cardinals to 70, comprising six cardinal bishops, 50 cardinal priests, and 14 cardinal deacons. Starting in the pontificate of Pope John XXIII, that limit has been exceeded. At the start of 1971, Pope Paul VI set the number of cardinal electors at a maximum of 120, but set no limit on the number of cardinals generally. He also established a maximum age of eighty years for electors. His action deprived twenty-five living cardinals, including the three living cardinals elevated by Pope Pius XI, of the right to participate in a conclave.[citation needed] Popes can dispense from church laws and have sometimes brought the number of cardinals under the age of 80 to more than 120. Pope Paul VI also increased the number of cardinal bishops by giving that rank to patriarchs of the Eastern Catholic Churches. Question: Pope Sixtus V limited the number of cardinals to?

Answer: 70


Question: Passage: Cuban immigrants in the 1960s brought the Cuban sandwich, medianoche, Cuban espresso, and croquetas, all of which have grown in popularity to all Miamians, and have become symbols of the city's varied cuisine. Today, these are part of the local culture, and can be found throughout the city in window cafés, particularly outside of supermarkets and restaurants. Restaurants such as Versailles restaurant in Little Havana is a landmark eatery of Miami. Located on the Atlantic Ocean, and with a long history as a seaport, Miami is also known for its seafood, with many seafood restaurants located along the Miami River, and in and around Biscayne Bay. Miami is also the home of restaurant chains such as Burger King, Tony Roma's and Benihana. Question: Along with Benihana and Burger King, what chain restaurant is headquartered in Miami?

Answer:
Tony Roma's