싫어하는 사람앞에서 표정이 바뀌지 않고

웃으면서 안부를 건낼수 있어야 하며

Your facial expression should be self-disciplined, imperturbable and deadpan even in the presence of somebody you dislike. Moreover, you should will yourself to greet that person with your beaming, smiling eyes so warmly and friendly as to overpower the other's doubt and discomfort. Beyond not showing (self-revealing) your feeling outwardly, your naturally and humanly strong emotion (and revulsion and intolerance) must be veiled, couched and filtered in your invariably mild, moderate, soft, gentle expression.  (I write this, but it's easier to be said than to be done.)