(Must is used for orders and for strong suggestions, advice and opinions. Should is used for less strong suggestions, advice and opinions. Orders and instructions can be made more polite by using should)
1 You know, I think you __________ take a holiday.
2 Tell Mark he __________ tidy his room at once.
3 Visitors are reminded that they __________ keep their bags with them.
4 I’m sorry, but you __________ go. We don’t want you here.
5 I really __________ go on a diet. I’ll start today.
6 I suppose I __________ write to Aunt Rachel one of these days.
7 You absolutely __________ check the tyres before you take the car out today.
8 All officers __________ report to the Commanding Officer by midday.
9 You __________ have your hair cut at least once a week.
10 I think men __________ wear jackets and ties in restaurants.