问题补充:
The number of the red-crowned cranes will become if we don’t take any action.
A. fewer and fewer
B. less and less
C. smaller and smaller
D. larger and larger
答案:
A. fewer and fewer
B. less and less
(答案→)C. smaller and smaller
D. larger and larger
解析:形容词的比较级用and来连接表示越来越怎样,根据语境可知丹顶鹤的数量会越来越少,如果人类不采取措施的话。