Table: olympic_weightlifting_women_plus75kg
Columns: world_record
snatch
mu_shuangshuang_chn
139kg
doha_qatar

Question: What's the snatch when the 139kg was 305kg and the Olympic Record was the world record?
SQL: SELECT "snatch" FROM olympic_weightlifting_women_plus75kg WHERE "world_record" = 'olympic record' AND "139kg" = '305kg'