Edward, you play so well. But I ________ you played the piano.
#104527
A
didn’t know
B
hadn’t known
C
don’t know
D
haven’t known
推荐题目
I am so tired,for I ________ English for 2 hours.
#99761
A
is studying 
B
have been studying
C
was studying 
D
had been studying
I ___________ to phone her all day, but whenver I phone her, the line is engaged.
#101328
A
tried
B
had been trying
C
have tried
D
have been trying