What are the titles of segment a for series episode 21-12?
CREATE TABLE table_15187735_21 (segment_a VARCHAR, series_ep VARCHAR)
SELECT segment_a FROM table_15187735_21 WHERE series_ep = "21-12"
### Context: CREATE TABLE table_15187735_21 (segment_a VARCHAR, series_ep VARCHAR) ### Question: What are the titles of segment a for series episode 21-12? ### Answer: SELECT segment_a FROM table_15187735_21 WHERE series_ep = "21-12"