A system administrator would like to verify the user definitions in the /etc/passwd file. Which of the following commands will accomplish this？（）

Asystemadministratorhasbeenaskedtolockaspecificloginacc...

单项选择题A system administrator has been asked to lock a specific login account. Which of the following commands is used to accomplish this？（）

Auserwouldliketheirshellprompttoreflectthecurrentdirect...

单项选择题A user would like their shell prompt to reflect the current directory. Which of the following environment variables can be set to accomplish this？（）

Whichofthefollowingcommandscanbeusedtogetthesystemready...

单项选择题Which of the following commands can be used to get the system ready to physically insert a PCI hot plug adaptor？（）