Children don' t understand initially what they are reciting, but

Children don' t understand initially what they are reciting, but _____ it will have an impact on their thinking.
A、casually
B、especially
C、regularly
D、gradually
【正确答案】：D
【题目解析】：考查副词辨析。句意：孩子们不知道他们背的是什么，但它会渐渐地影响他们的思维。casually意为“随意地”，especially意为“尤其地”，regularly意为“按时地”，gradually意为“渐渐地”。根据句意，故选D。