I already try to assign the user abc to the wheel group and uncomment the line %wheel in the sudoers file, and it did not work too!
thank you for your intervention
the output of the command sudo-l is:
Matching Defaults entries for AdmiNet on this host:
requiretty,! visiblepw, always_set_home, env_reset, env_keep = "COLORS DISPLAY HOSTNAME HISTSIZE INPUTRC KDEDIR LS_COLORS" env_keep + = "MAIL PS1 PS2 QTDIR
USERNAME LANG LC_CTYPE LC_ADDRESS "env_keep + =" LC_COLLATE LC_MESSAGES LC_IDENTIFICATION LC_MEASUREMENT "env_keep + =" LC_MONETARY LC_NUMERIC lc_name
LC_PAPER LC_TELEPHONE "env_keep + =" LC_TIME LC_ALL LANGUAGE LINGUAS _XKB_CHARSET XAUTHORITY "secure_path = / sbin \ :/ bin \ :/ usr / sbin \ :/ usr / bin
User AdmiNet Following the May run commands on this host: