— _________ do you have an Art Festival in your school?  

— Once a year.

A. How long B. How often      C. How far       D. How soon

—　　　do you have an Art Festival in your school? —Once a year.

A. How long         B. How often　        C. How far  D. How soon

--_____do you have an art festival in your school?

-- Once a year　

　 A. How much　　　 　　 B. How many　　 C. How often　　 　　 D. How long

—　　　do you have an Art Festival in your school? —Once a year.