instruction:
In this task, you're given a context, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both context and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the context or linked information.
question:
Context: Major attractions include white lions, white tigers Link Information: none Answer: none
answer:
Which of the large cats featured at the zoo is larger on average?


question:
Context: Henry's famous Walk to Canossa Link Information: The Road to Canossa, sometimes called the Walk to Canossa (/Kanossa) or Humiliation of Canossa (), refers to Holy Roman Emperor Henry IV's trek to Canossa Castle, Italy, where Pope Gregory VII was staying as the guest of Margravine Matilda of Tuscany, at the height of the investiture controversy in January 1077 Answer: 1077 
answer:
What year did the Walk happen?


question:
Context: a flotilla of gunboats of the Union Navy Link Information:  a flotilla of gunboats of the Union Navy  Answer: 1
answer:

How many gunboats did the Union Navy have?