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: I am aboard septa train to Trenton. Train was hit by something and came to a stop. Moments later the Amtrak train that derailed passed us.— Alfred Price (@TheAlfredPrice) May 13, 2015 Answer: the amtrak train that derailed passed them
what happened moments later

Context: @cnni I hope the families of the victims get the truth and finally closure #Westgate6Months— Ruthie Ruthie (@808Ruthie) March 17, 2014 Answer: karen's 100
who is the poster of this tweet?

Context: Greg Cosell @gregcosellRT @YahooSchwab: Patriots thrive on being unpredictable. That's the challenge for the Falcons' defense. @gregcosell breaks it down. https:/…2/4/2017, 5:38:34 PM Answer: patriots are unpredictable

what will be a challenge for the falcon's defense?