________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
Israel was created as a homeland for homeless Jews after World War Ⅱ. However, the creation of Israel in ________ used to be Palestine left many Palestinians homeless.
#30342
A
what
B
which
C
where
D
that
Steps must be taken ______this kind of disaster will never happen again.
#33840
A
because
B
even if
C
as
D
so that
The school rules state that no child shall be allowed out of the school during the day, __________ accompanied by an adult.
#32564
A
once
B
when
C
if
D
unless
In the office an electrical engineer is looking through the instructions to know ________ the heat system works before the repair work.
#30344
A
whether
B
why
C
how
D
that
(2014·枣庄模拟)The teacher simplified the instructions________the children could understand better.
#30032
A
so that
B
unless
C
in case
D
though