MR. RAP ... MATHEMATICS BEFORE HE ... TOP LITERATURE. A. HAD TAUG...

909. - 1000 CAU TRAC NGHIEM TIENG ANH ON THI THPT QUOC GIA CO DAP AN
1000 CAU TRAC NGHIEM TIENG ANH ON THI THPT QUOC GIA CO DAP AN

909. Mr. Rap ... mathematics before he ... top literature.

A. had taught/ had changed

B. was teaching/ changed

C. taught/was changing

D. had taught/changed