Task: Question Generation
Input (English): #1 return the  Russians were expelled from  Tehran 
#2 return the  British General Ironside promotes Reza Khan to lead an entire brigade 
#3 return year of #1 
#4 return year of #2 
#5 return the  difference of #4 and  #3
Output (English): How many years after the Russians were expelled from Tehran did the British General Ironside promote Reza Khan to lead an entire brigade?