TASK DEFINITION: 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.
PROBLEM: Context: Sad to lose Nola @sandiegozoo Now only 3 northern white rhinos remain on our planet. #Nola4Ever #anthropocene. Edward Burtynsky (@edwardburtynsky) November 23, 2015 Answer: three

SOLUTION: how many northern white rhinos remain in existence?

PROBLEM: Context: History is made! #MontrealProtocol countries agree to curb powerful greenhouse gases in largest climate breakthrough since Paris. 🌍🌎🌏 UN Environment (@UNEP) October 15, 2016 Answer: curb greenhouse gases

SOLUTION: what did @montrealprotocol countries agree to?

PROBLEM: Context: #PhotoOfTheDay: "We just ran" Rose & her children among 1.5m uprooted by violence in #Nigeria #BringBackOurChildhood Unicef UK Media (@Unicefuk_media) April 13, 2015 Answer: #bringbackourchildhood

SOLUTION:
what hashtag is unicef using to bring awareness to the violence in nigeria?