From your other post people here realize you are not ready to take responsibility for a dog, so when your parents say, "no," please accept this and believe that they know best. At a later time in your life when you have time and understand what it takes to give a dog good care, you can get a dog. But for now, "no." If you have time, you could volunteer at a shelter for homeless dogs.

It's hard to understand why parents say no to things, especially
something as precious as a dog or a cat! I'll try to help you. :)

The
best way to convince parents that you're ready for responsibility is by
becoming a really responsible person over a very long period of time,
like a couple of years. You have to become that person, not just try to
be one. It has to be who you ARE. And you can train yourself to be that
kind of a person if you really want to. They still may not want a dog,
and if you are mature, you will respect that. Try to remember that this
is their lives, and their home, too. :)

You may have been told
before, but it's really true, that taking care of a pet is fun in the
beginning, maybe even the first month or two. But then it becomes your
regular life and the chores become boring chores. Most kids will then
stop doing what they promised to do, and parents know that. That might
be part of why they're telling you no.

If your parents have said
no, then it's best to very nicely and respectfully tell them you
understand, and thank them for listening to you. Then drop it. If you
have not acted nicely about it, a sincere apology goes a long way. Later
on, like in maybe two years from now (seriously! It does feel like an
eternity, but this is what it takes!), after you have very consistently
obeyed and respected them, and over a long period of time even taking on
jobs that they didn't ask you to do but that you know they would find
helpful, you know -go the extra mile, ask very nicely if you could talk
with them about it and whether they think it would be OK to have a dog.
But any kind of whining and "why can't I", and not completing things
you've been asked to do, only proves to them that you are not ready and
they will (with good reason) not want to allow it.

Another thing
to remember is that a dog is likely to stick around for a very long
time, and they may not be OK with everything that's involved with that.
Even if you were very good and did a lot of the chores, they still would
be put out a lot of times, such as finding someone to care for it when
you leave on vacation or just being gone from the house for an entire
day. If this is not what they want, you may just have to wait until
you're a grown up, and then you might be able to get a dog, if you want
all that extra work at that point.

I totally understand that you
want a dog though, I do too!!! But I am really not up for the work and
responsibility involved. So I'll just dream about it and watch fun shows
about dogs. :)

The parents know they will end up with the responsibility and probably the cost of it too which is expensive, have you thought it all out and what kind you want, write down the pros and cons, find out all the expenses that includes, beds, toys, leashes, collars, dog tags you pay for them the shots, check ups and how about emergency trips and do you have a car that can carry the dog size you want in it. Vets are expensive and unexpected things can come up fast and its really costly for vet care of any kind.Surgeries, medications, old age, hips, knees that must be operated on. And food is expensive, you don't buy cheap stuff anymore, buy or cook good food for them to eat, do you have space for all that and the money to pay for it, you would be surprised even a small dog how costly it is, there is grooming for many dogs, teeth cleaning, nail clipping, and constant daily walks and give them good ones to wear them out. Are you prepared for all things that come up, how about anxiety in your dog you have? Ones that can't stand being alone in house or car and yell it down and tear things apart and some chew. Socializing your dog and training it. And if a puppy, they do tons of chewing and you have puppy proof, puppy train them and socialize them and they out grow collars and leashes. Get them ID by chips or tattoos so when lost they can look at the ID, keep that updated too. I don't know how old you are, but you leave home to schooling or work, what about the dog, they are left with it which isn't fair, that is probably why they end up telling you no.