The heart of another is a dark forest, always, no matter how close it has been to one's own.
市场失灵常常不是市场的失败,而是市场设计的失败。
如果物体处于静止状态或作匀速直线运动,只要没有外力作用,物体将保持静止状态或匀速直线运动状态。