In old age the two men wrote each other wistful letters.这两个人晚年时互通信函，诉说怀旧感伤之情。He has a wistful look.他神情沮丧。The statue has a gentleness, an ambience, a wistful elegance.那尊雕像具有一种柔和 、 一种独特格调 、 一种忧郁沉思的雅致....
氟化物的危害一般局限在制造厂的附近.Fluoride damage is generally restricted to areas near manufacturing plants.在茜素染料法中,氟化物的消色作用较慢.The bleaching action of fluorides is slow in the alizarin dye procedure.氟化物危害的特点是叶片顶尖灼燃现象.Fluoride injury of...