A student who wishes to treat diseases of the mouth may wish to study dentistry. Dentistry studies how to keep the teeth, gums, and other parts of the mouth healthy and how these parts interact with the body.

Europe is, by convention, one of the world's seven continents. Comprising the western most point of Eurasia, Europe is usually divided from Asia by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting the Black and Aegean Seas.

The PhD is a doctoral degree, specifically called a "doctor of philosophy" degree. This is misleading because PhD holders are not necessarily philosophers (unless they earned their degree in philosophy!). That said, PhD recipients are able to engage in thought experiments, reason about problems, and solve problems in sophisticated ways.