The number of red-crowned cranes is getting .A. small and smallB. little and littleC. smal

问题补充：

The number of red-crowned cranes is getting .

A. small and small

B. little and little

C. smaller and smaller

D. less and less

答案：

A. small and small

B. little and little

(答案→)C. smaller and smaller

D. less and less

解析：考查比较级的用法。句意“丹顶鹤的数量正在变得越来越少。”“比较级+and+比较级”表示“越来越......”。less修饰不可数名词。small和big用来指数量的多少。故选C。