When I review the lab today,I experienced the odd number and even of subnet。I think everybody maybe use it in fact,So I introduce it now for everyone:
        It is actually simple ,use "254"mask(;; of course ,you should know witch class of network address do you want to match)and 1 or 0.both of them be used to complete the worke.
        For instance :;;;;;……
        Now We  only allow the even subnet to be match ,So We need to do this:
        Access-list 1 permit or access-list 1 deny
       The second instance:;;;;;;……Now We only allow odd number of subnet  to be match,So We should to do like this:
       access-list 1 permit or access-list 1 deny
      Another ones look like as above,Everyone need to do it by yourself。