CREATE TABLE table_21703 ("Class" TEXT, "Part 1" TEXT, "Part 2" TEXT, "Part 3" TEXT, "Part 4" TEXT, "Verb meaning" TEXT)

What's part 1 of the verb whose part 4 is gevroren?
SELECT "Part 1" FROM table_21703 WHERE "Part 4" = 'gevroren'
SELECT "Part 1" FROM "table_21703" WHERE "Part 4" = 'gevroren'