WHEN I CAME TO VISIT HIM LAST NIGHT, HE __________ HIS HOMEWORK. H...

27. - KIEM TRA 1TIET SO 1 TRON 4 DE
KIEM TRA 1TIET SO 1 TRON 4 DE
27. When I came to visit him last night, he __________ his homework. He said that he __________ it since 6 o'clock.A. was doing/was doing B. did/didC. was doing/had been doing D. was doing/has been doing