I believe its a 3 inch pipe.
the mouth belongs to the diestive system
Another word for when saliva comes out of your mouth is drooling.
This tube is technically called the trachea, but is commonly referred to as one's windpipe. Be careful not to confuse it with your esophagus, which connects your mouth to your stomach in the digestive system.
The simple answer to that is the Mouth as it mechanically and chemically digests food (via saliva and teeth).
Sperm.
ages
No, pregnancy only occurs when the sperm enters the woman's body through vagina, not the mouth. If sperm comes trough the mouth, it will lead to her digestive system, so it won't make you pregnant.
because if it comes out your mouth it will taste horrible
The fluid that comes out of one's mouth while sleeping is called drool or saliva. It is a natural process that helps keep the mouth moist and aids in digestion.
the moisture from your mouth is heat so it makes it into hot air an fit comes out as vapor
Your mouth is, in fact, part of the respiratory system. It's also part of the digestive system.
You must be thinking about the South Park cartoon episode. The reason we can't defecate from our mouth is that our digestive system isn't set up that way. Although, when someone vomits, what comes up can be almost as disgusting.