What is the Main span of the bridge from China with a Year to open of 2013 and Main span feet of 2,585?
CREATE TABLE "bridges_under_construction" (
  "name" text,
  "main_span_metres" text,
  "main_span_feet" text,
  "year_to_open" real,
  "country" text
);
SELECT "main_span_metres" FROM "bridges_under_construction" WHERE "year_to_open"=2013 AND "country"='china' AND "main_span_feet"='2,585';