Which cities have higher temperature in Feb than in Jun or have once served as host cities?
return cities ;return #1 that  once served as host cities ;return temperatures of #1 ;return #3 in Feb ;return #3 in Jun ;return #1 where #4 is  higher than #5 ;return #6 ,  #2
['select', 'filter', 'project', 'filter', 'filter', 'comparative', 'union']