Below domain, life is classified into six kingdoms: plants, animals, archaebacteria, eubacteria, and fungi. The last kingdom, protists, include all microscopic organisms that are not bacteria, animals, plants or fungi.  (Archaebacteria and eubacteria are sometimes combined into a single kingdom, monera.)

Kilo is the metric system prefix for 10³.

Part of the peripheral nervous system, the somatic nervous system is made up of nerve fibers that send sensory information to the central nervous system and control voluntary actions.

The speed of a sound wave will vary with the medium.  Sound travels fastest through media that has particles that are very close together, like metal. Thus, it travels faster through water than through air and doesn't travel at all through a vacuum (there are no particles in empty space to vibrate).

The cerebellum is a large cluster of nerves at the base of the brain that's responsible for balance, movement, and muscle coordination.