Most birds find it safe to sleep in the trees, but ____ they have eggs or young chicks, they don’t use a nest.
#79977
A
why
B
how
C
unless
D
where
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Anger is good for you, ____ you control it properly, according to new psychology research.
#80632
A
whether
B
when
C
as long as
D
in case
She walked home by herself at night, _____ she knew that it was dangerous.
#32080
A
once
B
as
C
unless
D
although
He doesn’t plan to go back to his home________he makes a fortune in Hong Kong.
#30045
A
while
B
since
C
or
D
until