He said that he has done his homework since 7 o'clock.20/30Hesaid that he has done his homeworksince 7 o'clock.(A) Said(B) Has done(C) Homework(D) SinceGiải thíchChọn đáp án B ⇒ had done Giải thích: cấu gián tiếp nên động từ cần lùi thời