Modal verbs of advice and obligation

• You must save water to help our planet.
• should we choose the cinema or theater?
• Should we pay taxes, even if we do not know how they are invested?
• Should I pay my pension, although the system don’t function well?
• What criteria should prevail in the selection?
• You should tell him that you are late.
• They should not work until Night

• You have to take out you dog or he will get crazy