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。
解释:所谓美的东西,无论在上下、内外还是远近,都不会产生危害,所以才叫做美。
乐观是为创造更美好未来的一种策略
"A good book should leave you slightly exhausted at the end. You live several lives while reading it."