A. to impress B. to have impressed

C. to be impressed D. to be impressing

【答案】C

【解析】

考查不定式的形式。固定动词seem to do sth似乎要做某事；本句主语the students与动词impress构成被动关系，所以使用不定式的被动式seem to be impressed。句意：干得好，学生们似乎对你的精彩演讲留下了深刻的印象。故C项正确。