question: What is the Main span of the bridge from China with a Year to open of 2013 and Main span feet of 2,585?
answer: SELECT main_span_metres FROM table_name_23 WHERE year_to_open = 2013 AND country = "china" AND main_span_feet = "2,585"
context: CREATE TABLE table_name_23 (main_span_metres VARCHAR, main_span_feet VARCHAR, year_to_open VARCHAR, country VARCHAR)