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The rivers will become dirtier and dirtier _______ we take action to protect them.
#55533
A
since
B
if
C
until
D
Unless
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  I   didn’t   know  anything  about it ______my  father told me .
#55534
A
until
B
because
C
after
D
and
The poor student works hard during this holiday _______ he’ll be able to get enough money for the next term.
#55483
A
so that
B
even though
C
as if
D
such that
Her grandparents are still in good health_____they are over eighty.
#57739
A
though
B
as soon as
C
until
D
because
_________ we know, food gives us energy.
#58142
A
As
B
Like
C
For
D
Of
— Would you like to go hiking with me, Susan?—I’d like to, _______ you don’t want to go alone.
#56452
A
until
B
before
C
if
D
after