_____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 experiment turned out to be a complete failure, _____ wasn’t _____ they expected．
#69442
A
as ; beyond
B
as; that
C
which; what
D
that; more than
—I can never forget the day ___ we spent together in the summer camp．—Well, especially the day _______it suddenly began to rain in the middle of the night．
#71691
A
when; when
B
which; when
C
what; that
D
on which; when
The fact ___ he had said so much ___ everybody.
#73524
A
what… started up
B
that..surprised
C
that…surprising
D
which..started up
Stephen Hawking believes that the earth is unlikely to be the only planet _life has developed gradually.
#68503
A
that
B
where
C
which
D
whose
—Would you tell me__________you want your tea , with sugar or milk ?—Sugar , please .
#72431
A
whether
B
when
C
what
D
how