the line, this transposes the last two words on the line.  Word
     boundaries are the same as 'shell-forward-word' and
     'shell-backward-word'.

'unix-word-rubout (C-w)'
     Kill the word behind point, using white space as a word boundary.
     The killed text is saved on the kill-ring.

'unix-filename-rubout ()'
     Kill the word behind point, using white space and the slash
     character as the word boundaries.  The killed text is saved on the
     kill-ring.

'delete-horizontal-space ()'
     Delete all spaces and tabs around point.  By default, this is
     unbound.

'kill-region ()'
     Kill the text in the current region.  By default, this command is
     unbound.

'copy-region-as-kill ()'
     Copy the text in the region to the kill buffer, so it can be yanked
     right away.  By default, this command is unbound.

'copy-backward-word ()'
     Copy the word before point to the kill buffer.  The word boundaries
     are the same as 'backward-word'.  By default, this command is
     unbound.

'copy-forward-word ()'
     Copy the word following point to the kill buffer.  The word
     boundaries are the same as 'forward-word'.  By default, this
     command is unbound.

'yank (C-y)'
     Yank the top of the kill ring into the buffer at point.

'yank-pop (M-y)'
     Rotate the kill-ring, and yank the new top.  You can only do this
     if the prior command is 'yank' or 'yank-pop'.