CREATE TABLE table_48529 ("Class" TEXT, "Part 1" TEXT, "Part 2" TEXT, "Part 3" TEXT, "Part 4" TEXT)

What is Class, when Part 2 is 'bl tu'?
SELECT "Class" FROM table_48529 WHERE "Part 3" = 'blétu'
SELECT "Class" FROM "table_48529" WHERE "Part 3" = 'blétu'