问题补充：
She admitted trouble her studies and playing basketball.
A. to have ; balancing
B. having ; to balance
C. to have ; to balance
D. having ; balancing
答案：
A. to have ; balancing
B. having ; to balance
C. to have ; to balance
(答案→)D. having ; balancing
解析：admit后的动词应该用动名词形式，即admit doing。have trouble/ difficulty (in) doing sth, 是一固定短语，表示：做某事有困难。句意：她承认很难在学业和打篮球之间求得平衡。
