Group 2: for children weighing 15 - 25 kgs (33 - 55 lbs), roughly 4 to 6 years. Booster seats that only fit into Group 2 are less common. Most are group 2 and 3, or groups 1, 2 and 3. Groups 2 & 3: for children weighing 15 - 36 kg (33 - 79 lbs), roughly 4 to 11 years.
Broil the ribs for about 5 minutes, until the sugar in the dry rub is bubbling and the ribs are evenly browned. Bake the ribs: Set the oven to 300Â°F. Move the ribs to an oven rack in the middle of the oven. Roast for 2 1/2 to 3 hours for spare ribs or 1 1/2 to 2 hours for baby back ribs. Halfway through cooking, cover the ribs with aluminum foil to protect them from drying out.
Par-boiling for 10-15 minutes and then grilling will help reduce some of the fat in the ribs. It will also help make them fall of the bone if you're grilling at higher heats. However, I don't think that 10 minutes is going to substantially affect your cooking time.