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_25 ( year_completed INTEGER, dam_type VARCHAR, dam_constructed VARCHAR )

### Question ###
Which Year completed has a Dam type of earthfill embankment, and a Dam constructed of khancoban dam?

### Accurate SQL ###

SELECT MAX(year_completed) FROM table_name_25 WHERE dam_type = "earthfill embankment" AND dam_constructed = "khancoban dam"