(2013·高考北京卷)Don’t turn off the computer before closing all programs，________you could have problems.
#30670
A
or
B
and
C
but
D
so
推荐题目
She was moving out of her old apartment _______ she suddenly realized that the key to the new apartment wasn’t on her.
#33292
A
until
B
once
C
when
D
as if
She walked home by herself, ______ she knew that it was dangerous.
#31449
A
if
B
so that
C
although
D
because
We’ll buy a11 the products in your storehouse, ______ of course the price is reasonabte．
#34413
A
provided
B
unless
C
though
D
until
It was foolish of you to take a taxi ___ you could easily walk there in five minutes.
#33064
A
while
B
when
C
since
D
before
---How long has your brother been working in this factory? ---_____he dropped from school in 2010.
#30727
A
When
B
Until
C
Since
D
Before