A、 A filter must implement the destroy method

B、 A filter must implement the doFilter method

C、 A servlet may have multiple filters associated with it

D、 A servlet that is to have a filter applied to it must implement the javax.servlet.FilterChain  interface

E、 A filter that is part of a filter chain passes control to the next filter in the chain by invoking the filterChain forward method

F、 For each  element in the web application deployment descriptor， multiple instances of a filter may be created by the web container