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.

Q: Passage: After the American Revolutionary War, the number and proportion of free people of color increased markedly in the North and the South as slaves were freed. Most northern states abolished slavery, sometimes, like New York, in programs of gradual emancipation that took more than two decades to be completed. The last slaves in New York were not freed until 1827. In connection with the Second Great Awakening, Quaker and Methodist preachers in the South urged slaveholders to free their slaves. Revolutionary ideals led many men to free their slaves, some by deed and others by will, so that from 1782 to 1810, the percentage of free people of color rose from less than one percent to nearly 10 percent of blacks in the South. Question: Who in the south were urging their churches to free their slaves in the south?

A: Quaker and Methodist preachers
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Q: Passage: The winner, Taira no Kiyomori, became an imperial advisor, and was the first warrior to attain such a position. He eventually seized control of the central government, establishing the first samurai-dominated government and relegating the Emperor to figurehead status. However, the Taira clan was still very conservative when compared to its eventual successor, the Minamoto, and instead of expanding or strengthening its military might, the clan had its women marry Emperors and exercise control through the Emperor. Question: Who established the first samurai-led administration?

A: Taira no Kiyomori
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Q: Passage: Agrobacterium tumefaciens, a soil rhizosphere bacterium, can attach to plant cells and infect them with a callus-inducing Ti plasmid by horizontal gene transfer, causing a callus infection called crown gall disease. Schell and Van Montagu (1977) hypothesised that the Ti plasmid could be a natural vector for introducing the Nif gene responsible for nitrogen fixation in the root nodules of legumes and other plant species. Today, genetic modification of the Ti plasmid is one of the main techniques for introduction of transgenes to plants and the creation of genetically modified crops. Question: Who developed the procedures used in this transfer?

A:
Schell and Van Montagu
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