自动地;独自地;单独地
alone or without help
  The animal had been left in the house by itself for a week. 这个动物被孤零零地留在了房子里一个星期。 
 A cough will usually get better by itself. 咳嗽一般自己会好的。 
 Neither group could do anything by itself without agreement from the other.
 No single measure by itself can guarantee a healthy life.
 Cook the polenta until it is thick enough for a spoon to stand up in it all by itself.
 See also: itself