Table: fighter_record_21
Columns: res
record
opponent
method
event
round
time
location

Question: What is the total number of Rounds held in Nevada, United States in which the time was 1:55?
SQL: SELECT COUNT("round") FROM fighter_record_21 WHERE "location" = 'nevada, united states' AND "time" = '1:55'

Question: What was the time when his opponent was Rudy Martin?
SQL: SELECT "time" FROM fighter_record_21 WHERE "opponent" = 'rudy martin'

Question: What was the method when the fight's time was 1:52?
SQL: SELECT "method" FROM fighter_record_21 WHERE "time" = '1:52'