单项选择题 An operator is editing a file using vi. Which of the following subcommand sequences will copy the current line plus the next 2 lines to the end of the file?（）

单项选择题 How can an operator temporarily gain access to the command line while in a smit session, without losing the current smit session?（）

单项选择题 Which of the following commands will display, in MB, the total, used, and free blocks of the currently mounted filesystems?（）