The waters of the tropics are invitingly clear.热带水域清澈诱人。The sultry weather in the tropics encourages tourists to lead an indolent life.热带闷热的气候使得游客只能过懒散的生活.In the tropics plants grow to huge proportions.在热带，植物会长得非常高大。Hist...
Many of the houses remain unsold.这些房屋有许多尚未售出。Thirteen per cent of Christie's coin and banknote auction went unsold.佳士得13%的硬币和纸币拍卖流拍。...piles of unsold books...一堆堆卖不出去的书Prices have been cut by developers anxious to o...