many times he finally understood it. A. ToldB. TellingC. Having toldD. Having been told

问题补充：

many times, he finally understood it.

A. Told

B. Telling

C. Having told

D. Having been told

答案：

A. Told

B. Telling

C. Having told

(答案→)D. Having been told

解析：考查非谓语的用法。tell与主语之间的关系是被动和完成的关系，所以用having been done来表示被动和完成。