Составить 5 предложений на английском языке что следует и что не следует делать

you must do your exercises you must eat you must save your books you must do your homeworks you mustn't do bad things you mustn't be lazy you mustn't cry you mustn't stay at home on workdays you mustn't paly more computer

не следует: we shouldn't cut trees. people pollute rivers, lakes and seas. we shouldn't kill animals.