Database: city_record
Question: Give me a list of cities whose temperature in Mar is lower than that in Dec and which have never been host cities.
SQL: select t1.city from city as t1 join temperature as t2 on t1.city_id  =  t2.city_id where t2.mar  <  t2.dec except select t3.city from city as t3 join hosting_city as t4 on t3.city_id  =  t4.host_city