Must/ mustn't, / should / shouldn't 1. The students. wear school uniform .
2. You ... forget your passport when you travel to another country.
3. If you feel bad you
visit a doctor
4. You ... talk in the library
НУЖНО! ЕСЛИ ОТВЕТ НЕ ЗНАЕШЬ НЕ ПИШИ ​

1) the students must wear school uniform
2) you mustn’t forget your passport when you travel to another country
3)if you feel bad you should visit a doctor
4)you shouldn’t talk in the library
5) we should be so careless about nature