DON'T TRY TO GET OFF THE BUS ____ IT HAS STOPPED.A. WHILE B....

56. - BO DE THI TRAC NGHIEM NGU PHAP TA ON THI 10
BO DE THI TRAC NGHIEM NGU PHAP TA ON THI 10
56. Don't try to get off the bus ____ it has stopped.A. while B. as C. since D. before