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.

7. The star "Alkaid" is at the end of the "handle" in the Big Dipper.

Ganymede. Ganymede is the largest satellite and seventh moon of Jupiter.

Leonardo Da Vinci. Although Leonardo Da Vinci is best known as an artist, he was also a sculptor, musician, architect and scientist.