问题补充：
The little girl can’t decide though there are so many kinds of MP5 in the mall.
A. what to choose
B. to choose which
C. which to choose
D. to choose what
答案：
A. what to choose
B. to choose which
(答案→)C. which to choose
D. to choose what
解析：根据though there are so many kinds of MP5 in the mall.可知答案为C，即不知买哪一种。
