The greatest pleasure I know is to do a good action quietly and to have it by accident.

问题补充：

The greatest pleasure I know is to do a good action quietly, and to have it by accident.

A. find out

B. finding out

C. found out

D. be found out

答案：

A. find out

B. finding out

C. found out

D. be found out

解析：考查动词时态与语态。句意 就我所知,最大的乐事是悄悄地做好事,不为人知也行,偶为人知也行。Have sth done ，让某事被做。Have it found out by accident.让这件事偶然的被发现。所以选C项。

考点 :考查动词时态与语态