chuyển các câu sau đây thành thể bị động : 1,Noone can answer that question . 2,the teacher made us do a lot of exercises. 3,how are they going to do this project. 4,which picture did you draw yesterday? 5,people say that prevention is better than cure. 6,we saw her cross the intersections. 7,people considered that Micheal Jackson has been the best pop singer. 8,everyone doesn't look up to him. 9, must they hand in weaponds? 10,nobody showed them how to do.