The population problem may be one of the world today.
A. the most
B. most difficult
C. the greatest
D. more interesting
网友回答
A. the most
B. most difficult
(答案→)C. the greatest
D. more interesting
解析:考查形容词比较级别的用法。根据后面的范围“of the world”确定使用最高级,因此可排除D项;A项意思不搭,B项缺少the,也排除;C项指最大的问题,最佳选项。