柠檬问题是指买家无法确定产品质量,因此只愿意支付反映平均质量的价格。
勿羡慕那些生活在愚昧“天堂”的人们,因为只有愚人才认为那里是幸福的。
What has destroyed every previous civilization has been the tendency to the unequal distribution of wealth and power.
The quarry industry must evolve with technology, or risk being left behind.