RE: showing 2 buffers m then x

[Drew Adams]

    reading GNU Emacs by O'Reilly, in the buffer list, m to mark 2 of the
    buffers I would like to show, then x which suppose to execute the
    selection, but according to my C-h m while in the buffer list shows
    that x -- delete or save marked buffers.
    I am working with 21.4a-1, 21.3.5 is what the book covers, so I am
    guessing that the x key in 21.41.1 differ. is that correct and if so,
    what is the execute command once you mark your buffers?

In any buffer:

 - `C-h b' gives you a complete list of all key bindings in the buffer.

 - `C-h m' gives you info on the buffer's modes, which also sometimes lists
the most important keybindings. What does it say about keys `m' and `v'?

 - `C-h k' gives you the command that is bound to any key.