Melon With Prawns And Strawberries

• 2 little gem lettuces
• 1 size
• 1 celery heart
• 1/2 size avocado
• 220 gr strawberries
• 16 ml unsweetened orange juice
• 10 ml olive oil
• 4 gr caster sugar
• 2 ml lemon juice
• 1 gr parsley (chopped fresh)