maybe ask them what you would have to do in order to prove yourself responsible enough to own a pet... Then if they say nothing!, don't get all mad and grumpy just tell them your reasons calmly for wanting a puppy. Reason with them, tell them you'll help out more do more in school and if you don't no dog if you do show responsibility like for 3 months or whatever then you can all go to the SPCA and choose a dog together. A dog is a lot of responsibility so mean it when you say you'll clean the backyard, take it for walks etc... etc...