instruction:
In this task, you're given a passage, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.
question:
Passage: In 2014, Ivanovic enjoyed a resurgence and attained a number of career-best achievements. She began the year by winning her first title in three years at the ASB Classic, defeating former world No. 1 Venus Williams in three sets before upsetting the reigning world No. 1 Serena Williams en route to her second Australian Open quarterfinal where she lost in three sets to thirtieth seed, Eugenie Bouchard. During the clay court season, Ivanovic reached her third final of the year at the Porsche Tennis Grand Prix, losing to two-time defending champion Maria Sharapova; the quarterfinals of the Mutua Madrid Open and the semi-finals of the Internazionali BNL d'Italia, defeating Sharapova for the first time since 2007 en route but was ultimately upset by Lucie Šafářová in the third round of the French Open. She rebounded by winning her first career singles title on grass at the Aegon Classic before reaching the final of the Western & Southern Open (her first top tier Premier final since 2009) and thus returned to the top ten of the WTA rankings for the first time in five years as a result. In September, Ivanovic reached her sixth singles final of the year (a new career-best) at the Toray Pan Pacific Open, where she defeated Caroline Wozniacki to claim her fourth title of the season, the most titles she won in a single season.
 Link Information: Venus Ebony Starr Williams (born June 17, 1980) Question: Which Williams sister is the oldest?
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Answer: Venus Williams


question:
Passage: Prettejohn was the Professor of the history of art at the University of Bristol from 2005, before becoming head of the history of art at the University of York in 2012. She has also been the Professor of Modern Art at the University of Plymouth and the curator of Paintings and Sculpture at Birmingham Museum and Art Gallery. She studied at Harvard University, where she got her Bachelor of Arts degree (summa cum laude), and at the Courtauld Institute of Art, where she got her Master of Arts degree in 1987 and PhD degree in 1991. She is married to the Professor of Classics and Dean of Arts, Charles Martindale. 
 Link Information: The University of Bristol is a red brick research university in Bristol, England Question: In what countries did Prettejohn work at universities?
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Answer: England


question:
Passage: The river rises in northwestern Wyoming in the Absaroka Range, on the Continental Divide in southwestern Park County. The river starts where the North Fork and the South Fork of the Yellowstone River converge. The North Fork, the larger of the two forks, flows from Younts Peak. The South Fork flows from the southern slopes of Thorofare Mountain. The Yellowstone River flows northward through Yellowstone National Park, feeding and draining Yellowstone Lake, then dropping over the Upper and Lower Yellowstone Falls at the head of the Grand Canyon of the Yellowstone within the confines of the park. After passing through the Black Canyon of the Yellowstone downstream of the Grand Canyon, the river flows northward into Montana between the northern Absaroka Range and the Gallatin Range in Paradise Valley. The river emerges from the mountains near the town of Livingston, where it turns eastward and northeastward, flowing across the northern Great Plains past the city of Billings.
 Link Information: none Question: What is the volume of the lake that the Yellowstone River feed and drain?
answer:

Answer: none