CREATE TABLE table_name_71 (score VARCHAR2, surface VARCHAR2, date VARCHAR2)

What was the April 7, 2008 score on a clay surface?
SELECT score FROM table_name_71 WHERE surface = "clay" AND date = "april 7, 2008"
SELECT "score" FROM "table_name_71" WHERE "april 7, 2008" = "date" AND "clay" = "surface"