The two terms don't have to be mutually exclusive. An arch is part of tunnel. When does a tunnel become a cave?
Lol Damn you and your timing Dr! Things that make me go hmmmm: Are the black bits in bananas tarantulas eggs?
God I hope so. When does a boy become a man? Because I've been growing fur in funny places recently and my voice is a little deeper and I'm starting to notice girls in a different way.
Aww you a late developer Rags? If I eat a whole apple including the pips will an apple tree grow inside me???
Why are people never perfect? Why does the sun rise? How can I be a better person? Why must a man become while a women is? Where am I going? Where are we going? Will I see tomorrow? Will my children see tomorrow? What have I done wrong? What have I done right? Why am I not master of my own existence? Do I have free will? If not, who am I being controlled of? Is there a God or Gods? Why are we so confused?
If tuna really isn't dolphin then why does it say dolphin freindly on the tin. Also I still maintain I'm technically right about having to show passports when flying to ireland or the channel islands. Those are my big Hmmmmm's in life, deep huh?