It was difficult to tell exactly _______ the saying began, but it is possible that it was in the theatre or movie industry.
#31061
A
where
B
when
C
why
D
that
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_______ you start, you should go ahead.
#31315
A
Once
B
Before
C
Until
D
Though
__________ he took part in the competition, he won a second prize. 
#33676
A
The first time
B
For the first time
C
At a time
D
At one time