Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

Context: Alejandro Adem is a professor in the Department of Mathematics at the University of British Columbia since 2005 and the holder of a Canada Research Chair at UBC. 
 Question: What is Alejandro Adem's place of employment?
university of british columbia

Context: Comet ISON, formally known as C/2012 S1, was a sungrazing comet discovered on 21 September 2012 by Vitali Nevski ( , Vitebsk, Belarus) and Artyom Novichonok ( , Kondopoga, Russia). 
 Question: By whom was Comet ISON discovered?
artyom novichonok

Context: Georg Ossian Sars was born on April 20, 1837, in Kinn, Norway (now part of Flora), the son of Michael Sars and Maren Sars; the historian Ernst Sars was his elder brother, and the singer Eva Nansen was his younger sister. 
 Question: Who is Georg Ossian Sars's sister?

eva nansen