Table schema:
CREATE TABLE table_name_30 (set_1 VARCHAR, set_2 VARCHAR, set_4 VARCHAR, score VARCHAR)

Question: What is Set 1, when Set 4 is NA, when Score is 3-0, and when Set 2 is 29-27?
SQL: SELECT set_1 FROM table_name_30 WHERE set_4 = "na" AND score = "3-0" AND set_2 = "29-27"