A problem is in P if it can be solved quickly by a computer, and in NP if a solution can be verified quickly.
The bond market is the ultimate reflection of market psychology.
奢侈者常嫌不够富足,节俭者虽贫穷却有余藏;奢侈者心常常贫困,节俭者的心常常富贵。
每个人都害怕受伤。