问题补充：
Do let your mother know the truth. She seems to everything.
A. have told
B. be told
C. have been told
D. being told
答案：
A. have told
B. be told
(答案→)C. have been told
D. being told
解析：句意：一定要让你的妈妈知道事情的真相。她好像什么都知道了。句子要用被动形式，表示被告知了所有事情。通过语境判断句子要用完成时态，故选C.
