I had been puzzled over the problem for over an hour without any result, all at once a solution flashed across my mind.
#33232
A
while
B
when
C
then
D
as
推荐题目
My father and his teacher talked for about an hour of things and persons ______ they remembered at the school.
#34663
A
that
B
which
C
who
D
what
He’ll come _______ I promise him to buy that new dictionary.
#33514
A
so long
B
on condition that
C
as soon as
D
by the time
All the dishes in this menu， _____ otherwise stated， will serve two to three people.
#79929
A
as
B
if
C
though
D
unless
Failure can make a positive contribution to your life _______ you learn to use it.
#33895
A
since
B
unless
C
until
D
once