how to solve the problem, the little boy turned to his father for help.
#96894
A
Not knowing
B
Having not known
C
Not having been known
D
Not known
推荐题目
______ when to leave, I could only stay at home, _____ nothing. 
#93935
A
Knowing not; done
B
Not having known; doing
C
Having not known; done
D
Not knowing; doing
Do you have any difficulty ________?
#96658
A
on listening
B
to listening
C
for listening
D
in listening