问题补充：
— The number of pandas is getting because their living areas are becoming polluted.
— So we must do something to protect them.
A. less and less
B. larger and larger
C. smaller and smaller
D. fewer and fewer
答案：
A. less and less
B. larger and larger
(答案→)C. smaller and smaller
D. fewer and fewer
解析：句意：——因为熊猫的生活地区正在被污染，熊猫的数量正越来越小。——因此我们采取措施保护他们。A. less and less越来越少；B. larger and larger越来越大； C. smaller and smaller越来越小； D. fewer and fewer越来越少。修饰名词number用形容词large和small。结合句意，故选C。
