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.
Place ribs in large skillet or roasting pan. Cover with lightly salted water, and bring to a boil. Reduce heat to low, and simmer for 1 hour, or until meat is tender, but not quite falling off the bone. Remove from heat, and drain. Place the boiled ribs in a roasting pan, and cover with sauce. Cover, and refrigerate for at least 2 hours. Melt butter in a saucepan over medium heat. Cook the onion and garlic in butter until the onion is tender; remove from heat. In a blender, combine 1 cup water, vinegar, ketchup, barbeque sauce, and lemon juice. Pour in the melted butter mixture, and puree for 1 minute. Pour into a saucepan, and season to taste with salt and pepper.