Vocabulary

• such as: For example; like
• used to: Did regularly before, but don't do now
• for instance: As an example.
• look at: To use your eyes to focus on something
• into space: Toward or entering the region beyond Earth's atmosphere.
• back up: To save a copy of your computer data
• on to: Toward something; forward
• as we know it: In the form or way commonly understood or accepted.
• on earth: Used to emphasize a question expressing surprise or anger.
• of course: Sure ; Certainly
• in power: Having control of a country or organization.
• in turn: One after the other in a sequence or rotation.
• energy sources: Materials or processes that can produce energy.
• planet: One of the bodies that orbit the sun
• atmosphere: Air around us
• natural: Being as one would expect; being usual or normal
• energy: Physical or mental strength
• flow: To move steadily and easily in a certain direction
• efficient: Able to produce results without waste
• generate: To create or be produced or bring into existence
• store: To put things in a place for later use
• earth: Wire connecting an electrical device to the ground
• chain: To feel to be bound or tied to
• carbon: Chemical element with an atomic number of 6
• food: What people and animals eat to live
• internal: Being or happening in the body
• heat: State of anger, excitement, or arguing
• wire: Thin, flexible thread of metal