when he is 21,he becomes a doctor.Betty doesnt do her homework at home;she does it outside every daywhat you did last weekli lei bought a pen yesterdaylisten!the boys are singing in the classroomdo you enjoy living here,jackam very busy.i have a lot of work to domy brother hadn't had lunch at home the before yesterdaywhere the brothers will play tomorrowhe will plant trees next week
1. was , became2. doesn't do , does3. did , do4. bought5. are singing6. living7. to do8. didn't have9. will, play (are, going to
play) 10. will plant 祝你进步!
