They may never know those "Old Cities" which yellowed with age are the real vitality of the city.
殊不知那些充满杂然发黄的“城市暗部”才是城市真正的活力所在。
This article analyses the causes that contribute to gray market and illustrates that gray market phenomenon is a result of the speeding globalization of international trade.
灰色市场是当前国际贸易和知识产权保护的热点问题。