______ over and over again, but he still couldn’t understand.
#103480
A
Having explained
B
Having been explained
C
Explaining
D
It had been explained
推荐题目
It’s only six o’clock now; Little Tom should be up ,though, because he _____ for nine hours.
#102920
A
has been sleeping
B
had been sleeping
C
has slept
D
had slept
A few minutes earlier, and you would have seen the NBA star. But you ______.
#100259
A
didn’t come
B
don’t come
C
haven’t come
D
won’t come
A poet and journalist ________to give us a speech tomorrow  in our school .
#103352
A
is said.
B
are said
C
is saying
D
are saying.