Taylor Swift wrote 'Ronan' inspired by a real-life story of a boy who battled which disease?

Cancer

Who voices the character Gru in Despicable Me? In cricket, what term describes scoring 100 runs in a single innings? The island of Socotra belongs to which Middle Eastern country? What prized item of Ross's is broken and hidden by Chandler and Joey? What's the symbol ∑ (sigma) usually represent?