河南成教 / 英语(四)
正确率:100%
1、 _ _ _ _ _ _ _ _ _ _ how to operate a switchboard, I had to ask the office supervisor to show me the correct procedures.
A. Not known
B. Not to know
C. Not knowing
D. Having not known
A. Not known
B. Not to know
C. Not knowing
D. Having not known
参考答案: