_________several times, but Mary still has no idea of how to do it properly. 
#19683
A
Being shown
B
Having shown
C
Having been shown
D
I’ve shown her
推荐题目
He doesn’t do his homework______ , though he has  ____.
#19827
A
careful enough; time enough
B
carefully enough; enough time
C
enough careful; enough time
D
enough carefully ;time enough
It is not socially  ____for parents to leave children unattended at that age. 
#20538
A
accessible
B
adorable
C
adaptable
D
acceptable