提供安全连接的ssh服务的端口号是：（）。

A.passwd
B.vncpasswd
C.smbpasswd
D.htpasswd

A.only_from=172.18.1.0/24
B.no_access=172.18.1.0/24
C.access_times=172.18.1.0/24
D.disable=172.18.1.0/24

A./etc/group
B./etc/netgroup
C./etc/libsafe.notify
D./etc/shadow

A.用户的根目录
B./
C.~
D./tmp

A.关机
B.重启
C.切换到图形
D.切换到字符

A.ext2
B.ext3
C.vfat
D.iso9660

A.2和0
B.0和0
C.1和0
D.500和500

A.cp-i./dir1/*./dir2
B.cp-P./dir1/*./dir2
C.cp-d./dir1/*./dir2
D.cp-r./dir1/*./dir2

A.22
B.23
C.80
D.8080

A./etc/httpd/httpd.conf
B./etc/ssh/sshd_config
C./etc/named.conf
D./etc/xinetd