这对我来说适用于你的输入文件:

This works for me with your input file:

sed -n  '1h; 1!H; ${ g; s/Mary\n\n/\n/g p }'

说明:

Mary\n\n                # Mary with two consecutive newlines, the first one is automatically added by
                        # the 'H' command, and the next one means the empty line, asumming it has no
                        # spaces.
\n                      # Substitute it with a blank line.