Ex 7. tìm và sửa lỗi sai 6-10
6. had talking --> had been talking
7. worked --> had been working
8. had you waiting --> had you been waiting
9. has standing --> had been standing
10. taught --> had been teaching

Ex 8.
1. had working --> had been working
2. did --> had done
3. didn't sit --> hadn't been sitting
4. hasn't waited --> hasn't been waiting
5. traveled --> had traveled
6. trained --> had trained
7. worked --> had been working

Ex 9. Put the verb in the future simple tense
1. will get
2. will win
3. will come
4. will be
5.will be