my sistEr hAs BEEn working in thAt FACtory EvEr ______ it wAs sEt up.
A) sinCE C) whEn
B) whilE D) Fill
A．my sistEr hAs BEEn working in thAt FACtory EvEr ______ it wAs sEt up.
B．sinCE
C．whilE
D．whEn
E．Fill