Vocabulary

• based on: To use something as the foundation or starting point for something else.
• used to: Did regularly before, but don't do now
• theory: Ideas or principles that explain facts or events
• system: Set of organized, planned ideas that work together
• explain: To make clear or easy to understand by describing
• science: Study of the physical world, based on facts
• principle: Moral rule or belief governing a person's behavior
• technology: Use or knowledge of science in industry etc.
• prove: To demonstrate truth by providing evidence
• base: Place military personnel live, train, and operate
• difficult: Hard; not easy; you need to work hard to do it
• percent: One one-hundredth of a whole; the symbol %
• mobile: Able to be moved or able to move
• repeat: Action that is done again
• impossible: (Child, etc.) very annoying
• test: To be given a medical examination
• solar: Concerning the sun, or its heat