Oh, hello again. 
You are really obsessed with this, aren't you?
psst ... that shows a lack of maturity.
a 17 year old is still a child. Legally and very often emotionally.
a 17 yr old who persists on grabbing hold of adults on the internet and badgering them about whether or not a 17 year old is an adult is very much a child.
Pet, I have to ask - are you going to keep going until you get a thread that says nothing but yes, a 17 year old is an adult, and then wave it under your mum's nose? Look mum, strangers on the internet say 17 is an adult, so you HAVE to treat me like one... stomp stomp huff slam.
when I was 18, I stomped round my home yelling YOU CAN'T TELL ME WHAT TO DO, I'M 18 NOW.
really showing maturity, eh? 
Stop asking. stop obsessing. stop seeking some sort of validation from strangers on the net and you will be a step closer to being a grown up than you are right now.