（A pessimist sees a glass that's half empty; an optimist sees a glass half full.
（A pessimist sees a glass that's half empty; an optimist sees a glass half full.
这句话出自谚语：「悲观的人看到杯子里有一半是空的；乐观的人则看到杯子里有一半是满的。」
（A pessimist sees a glass that's half empty; an optimist sees a glass half full.
这句话出自谚语：「悲观的人看到杯子里有一半是空的；乐观的人则看到杯子里有一半是满的。」