Have you ever wondered why your teeth chatter when you're cold, or if you could really catch a disease from sitting on a toilet seat? And why do men have nipples?

　　New York physician Billy Goldberg, pestered by unusual questions at cocktail parties and other social gatherings over the years, puts the public's mind at ease in his book "Why Do Men Have Nipples?" which hits the book stores on Tuesday.

　　The book, subtitled, "Hundreds of Questions You'd Only Ask a Doctor After Your Third Martini," (Three Rivers Press), is co-authored by humorist Mark Leyner. Some of the burning questions answered in the humorous book include "What causes morning breath?" and "Why do beans give you gas?"