If winner is alejandro Valverde and the points Classification is by Erik Zabel, who is the mountain classification?
CREATE TABLE "jersey_progress" (
  "stage" real,
  "winner" text,
  "general_classification" text,
  "points_classification" text,
  "mountains_classification" text,
  "combination_classification" text,
  "team_classification" text
);
SELECT "mountains_classification" FROM "jersey_progress" WHERE "winner"='Alejandro Valverde' AND "points_classification"='Erik Zabel';