I would have come sooner but I ________ that they were waiting. 
#104791
A
haven’t known
B
hadn’t known
C
don’t know
D
didn’t know
推荐题目
Every possible means ________, but the teacher as well as the students ________ found a solution to the problem yet. 
#102485
A
has been tried; hasn’t
B
has tried; haven’t
C
have tried; haven’t
D
have been tried; hasn’t
  When I ______home, I caught a thief stealing from a passer-by.
#99768
A
headed
B
was heading
C
has headed
D
had headed
It is the only time in history that two Nobel Prizes ________ to the same person.
#99810
A
have been given
B
had been given
C
have given
D
will give