_____several times，but unfortunately，the boy still couldn’t smooth away the problem on his own.
#73673
A
Having been explained
B
The problem having been explained
C
The problem had been explained
D
Although the problem had been explained
推荐题目
The road conditions there turned out to be very good, ___ was more than we could expect.
#71771
A
it
B
what
C
which
D
that
Tom said he had been working for three hours, _____ ,evidently, was untrue.
#73683
A
he
B
this
C
it
D
which
Thanks to the application of new farming methods,output is now six times _____it was before 2000.
#71709
A
that
B
what
C
which
D
how
The result is not the same _____ they had expected, _____ was rather disappointing.
#73456
A
which; as
B
as; that
C
that; which
D
as; which