________you never plan to visit the polar bears in the North Pole or the penguins in the South Pole，now it is the proper time to start thinking about that.
#30102
A
Until
B
Unless
C
As long as
D
Even if
推荐题目
Leave your key with your neighbor ________ you lock yourself out one day.
#31036
A
as long as
B
even though
C
in case
D
as if
--Are you going somewhere during the winter vacation? --Yes, I’ve found a nice beach ________ I can enjoy swimming even in February．
#33429
A
that
B
when
C
where
D
which
______environmental damage is done，it takes many years for the ecosystem to recover.
#80690
A
Eyen if
B
If only
C
While
D
Once
You must learn to consider all possible results you begin to carry out your plan.
#30837
A
although
B
before
C
because
D
unless
______ you call me to say you’re not coming, I’ll keep waiting for you at the theatre.
#31833
A
Unless
B
When
C
If
D
As