问题补充：
Most students think Liu Xiang is one of sports stars in China.
A. popular
B. more popular
C. most popular
D. the most popular
答案：
A. popular
B. more popular
C. most popular
(答案→)D. the most popular
解析：one of +形容词的最高级+名词的复数形式是固定短语，表示…其中之一。Popular的最高级借助most，故选D。
