单选题 I appreciated ______ to the United States to study five years ago.
A. to have sent B. be sent C. being sent D. to have been sent

【正确答案】 C
【答案解析】动词appreciate后面需接动词+ing作宾语，故A、B、D选项均可排除。由于动词+ing与主语之间为动宾关系，所以用动词+ing的被动形式。