Definition: If something useful is at a premium, there is not enough of it. Level: C2
考试开始前时间非常宝贵。
Time ___is ___at ___a ___premium just before the start of exams.
在生活中，诚实和友谊非常稀缺。
In life, honesty and friendship ___are ___at ___a ___premium.
在一些受干旱影响的地区，清洁水资源非常稀缺。
Clean water ___is ___at ___a ___premium in some drought-stricken regions.
