Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_21 (silver VARCHAR, year VARCHAR, gold VARCHAR)

### Question ###
Who won silver in the year before 2010, the year Chan Ming Shu won gold?

### Accurate SQL ###

SELECT silver FROM table_name_21 WHERE year < 2010 AND gold = "chan ming shu"