Cetaceans. "Cetus" is a Latin word that means "large sea animal".

Jerry Yang. Yahoo! shares trade under the letters YHOO on the NASDAQ.

Clavicle. The clavicle is one of the most commonly broken bones as a result of sports injury.

Hepatitis B. Hepatitis B is 100 times more contagious than HIV.

Submersible. A submersible is sometimes called a "midget submarine".

Momentum. Velocity, displacement, momentum, force and acceleration are vectors.