Yao Ming works hard on his English and A. so Liu Xiang doesB. so is Liu XiangC. so does Li

问题补充：

Yao Ming works hard on his English and

A. so Liu Xiang does

B. so is Liu Xiang

C. so does Liu Xiang

D. so Liu Xiang is

答案：

A. so Liu Xiang does

B. so is Liu Xiang

(答案→)C. so does Liu Xiang

D. so Liu Xiang is

解析：“so＋助动词（情态动词或连系动词）＋另一主语”，表示前面的情况也适用于后者。So+主语+助动词（情态动词或连系动词）是对上文所说的情况加以肯定。如果上文是否定形式则要将so换成neither。联系前文，姚明努力学习英语。可知下文指的是刘翔也是这样做。故选C。