Task: Question Generation
Input (English): #1 return flights 
#2 return #1 from  las vegas 
#3 return #2 to new york 
#4 return #3 that  is  twa 
#5 return #4 that  is  718am 
#6 return how  much of #5
Output (English): how much is the 718am flight from las vegas to new york twa