Task: Question Generation
Input (English): #1 return architects 
#2 return #1 that  are American 
#3 return #1 that  are Canadian 
#4 return mills built by #2 
#5 return mills built by #3 
#6 return #4 ,  #5 
#7 return the  distinct types of #6
Output (English): What are the distinct types of mills that are built by American or Canadian architects?