Chuyển từ câu chủ động sang câu bị động: You should place matches out of reach of children

chuyển từ câu chủ động sang câu bị động
1.You should place matches out of reach of children
2.They can gain nothing without effort
3.People must conserve natural resources
4.They said that I am a teacher
5.People said that Nam killed his wife
6.Does he often help you?
7.What is she doing
8.She bought a new car yesterday
9.People thougt that she is a robber
10.My father often buys me perents on my birthday