He _______ his homework before he went to bed last night.
had done
has done
was doing
did
He _______ his homework before he went to bed last night. had done has done was doing did
By aihong
By aihong
He _______ his homework before he went to bed last night.
had done
has done
was doing
did
He _______ his homework before he went to bed last night.
had done
has done
was doing
did
vì có động từ before nên chọn had+done
He _______ his homework before he went to bed last night.
had done
has done
was doing
did
chọn had done vì đây là cấu trúc của before.
Before +qkđ, qkht
qkđ: went
qkht: had done