单项选择题
A.ifconfigeth0172.16.22.8netmask255.255.255.128 B.ifconfig172.18.48.56netmask255.255.255.128 C.ifdowneth0172.16.22.8netmask255.255.255.128 D.ifconfigup172.18.48.56netmask255.255.255.128
A.userdel tom B.useradd zhangkang C.useradd–tom D.userdel zhangkang
A.mv/etc/passwd/etc/wd.bak B.cp/etc/passwd/etc/pwd.bak C.rm/etc/passwd/etc/passwd.bak D.ls/etc/passwd/etc/passwd.bak