question: Give me a list of cities whose temperature in Mar is lower than that in July and which have also served as host cities?
#1 return cities 
#2 return #1 that  have served as host cities 
#3 return temperatures of #1 
#4 return #3 in Mar 
#5 return #3 in July 
#6 return #1 where #4 is  lower than #5 
#7 return #1 in both #2 and #6