Chuyển sang câu bị động: 1.They should send these letters soon 2.Someone may carry those bags to the shop 3.People can find pictures books on the shelf 4. They can see my house from the top of the hill 5.They shouldn't sell foos on the sidewakls 6.We must keep our school clean and tidy 7. You have to put your pens in a box 8.People will hold a meeting in our school 9. People can't learn a foreign languge in a week