My friend’s flight had taken off _________ I got to the airport to see him off.
#56042
A
while
B
after
C
before
D
until
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You should keep working hard ____ you have passed the exam. 
#56116
A
since
B
because
C
so
D
even though
  ________ he fails the job interview ?
#56247
A
When
B
What if
C
Why
D
What about