In this task, you are given a context tweet and an answer. Your job is to generate a question for the given answer based on the given tweet paragraph. Note that your question should be answerable based on the given tweet, and the answer to your question should be the given answer.

Context: Cavill filming Superman @justiceleaguewb scenes with a mustache is something I want in DVD extras— Chris Sylvia (@sylvioso) July 24, 2017 Answer: superman
who is cavill playing in the movie?

Context: Yellowstone River closed to ALL recreation in response to ongoing fish kill: Montana FWP (@MontanaFWP) August 19, 2016 Answer: yellowstone river
what river was closed?

Context: very interesting news at @AZAlkmaar : D AZ excited to welcome Billy Beane as club advisor !!— Jürgen Klinsmann (@J_Klinsmann) March 17, 2015 Answer: billy beane

who is jurgen excited to welcome?