柠檬问题发生的原因是卖家比买家更了解产品，从而导致市场失灵。
"The point is not to predict the future, but to prepare for it."
"Books are the most precious gifts we can give to a child."
即使鬼神不存在，这也可以用来聚集众人来欢乐，使得邻里亲近。