Chuyển sang câu bị động 15. The organizer says that the performance will start at 7 p.m. ________________________________________________________________ 16. He recommended that we shouldn't stay in the suburb. ________________________________________________________________ 17. I had a technician repair my mobile phone. ________________________________________________________________ 18. They often get the technician to maintain the water heater. ________________________________________________________________ 19. How long have you waited for the dentist? ________________________________________________________________ 20. People saw her plant the tree. _______________________________________________________________