The real secret to successful learning lies in students＿＿＿＿an interest in what they are doing.
A. to take
B. taking
C. taken
D. having taken
网友回答
A. to take
(答案→)B. taking
C. taken
D. having taken
解析：此处in是介词，后面接动名词作宾语，这里接的是动名词的复合结构，即名词（逻辑主语）+动名词。句意：成功学习的秘密在于学生对他们所做的事感兴趣。