—— many times,I still could not understand how to operate the machine.A：Having been told B：having told C：I have been told D：telling 为什么不选c

—— many times,I still could not understand how to operate the machine.A：Having been told B：having told C：I have been told D：telling 为什么不选c
—— many times,I still could not understand how to operate the machine.
A：Having been told B：having told C：I have been told D：telling 为什么不选c

—— many times,I still could not understand how to operate the machine.A：Having been told B：having told C：I have been told D：telling 为什么不选c
理由很简单,如果填C,句子变成
I have been told many times,I still could not understand how to operate the machine.前后句子竟然就没有连词了!