Список правил как поддерживать чистоту с глаголом must.

1. You must keep your room clean.
2.You must tidy your room regularly.
3.You must hoover the carpet every week.
4. You must mop the floor twice a week.
5. You must make you bed.
6. You must dust the furniture every week.
7. You must put your clothes to the wardrobe.
8. You must put all your books to the bookshelf.

Ну я думаю достаточно)