A little history/geography quiz

[CGM]

Whats the most common non-contagious disease in the world ?

Tinitis?

you hearing things? I was gonna say schizophrenia, but my latest research tells me it's a normal state of mind. (just kidding, sort of, maybe)

[X]

Good effort - the most abundant element on earth (and the universe) is hydrogen. (if you think of all the compounds that have hydrogen atoms bonded into them, it makes more sense than having just lots of loose hydrogen gas floating around.)

The most common non-contagious disease in the world ...... tooth decay!