Chuyển câu màu xanh sang câu bị động ----- Nội dung dịch tự động từ ảnh ----- operation. They musin't scrub their hands before. 6. It isn't necessary for Emma to wash her dog once a week. Emma mustn't wash her dog 7. Is it possible to recycle garden trimmings? can't recycle garden trimmigs: once a week. 8. It isn't advisable to play with matches. You shouldn't play with matches. 9. It is not possible for us to spend this evening at the concert. We com'T for us to spend this evenig 10. James is obliged to copy the files. James_must the files. 11. It is forbidden to use mobiles phones in hospital. you сору 12. It isn't necessary for Helen to prepare a birthday cake. Helen needin's mustn't use mobiles phones in hospind. prepare a buhday cake. 13. Students are not allowed to eat and drink in the classroom. Students mustn't eat and drink in the classroom 14. You are allowed to wait outside. You m'ait outside. 15. It is your duty to be in the office on time. You must be in the office on time