Table: locomotive_history_2
Columns: nbr_number
year
original_operator
class
wheel_arrangement
road_number
location

Question: What is the highest NBR number that corresponds to the J class and the road number of 1211?
SQL: SELECT MAX("nbr_number") FROM locomotive_history_2 WHERE "class" = 'j' AND "road_number" = 1211

Question: How many road numbers are before 1922?
SQL: SELECT COUNT("road_number") FROM locomotive_history_2 WHERE "year" < 1922

Question: Which original operator is in the 25nc class?
SQL: SELECT "original_operator" FROM locomotive_history_2 WHERE "class" = '25nc'

Question: Which class starts after 1939 and has a road number smaller than 3508?
SQL: SELECT "class" FROM locomotive_history_2 WHERE "year" > 1939 AND "road_number" < 3508