定義:to know (properly, to ascertain by seeing); used in a great variety of senses, figuratively, literally, euphemistically and inferentially (including observation, care, recognition; and causatively, instruction, designation, punishment, etc.)
定義:to turn back (hence, away) transitively or intransitively, literally or figuratively (not necessarily with the idea of return to the starting point); generally to retreat; often adverbial, again