1 If living in an area with frequent thunderstorms, consider buying a lightning protector. 2  These cost between $35 and $55. 3  Keep in mind that an invisible fence doesn't keep other dogs, animals or people out of the yard. If living in an area with frequent thunderstorms, consider buying a lightning protector. 2  These cost between $35 and $55. 3  Keep in mind that an invisible fence doesn't keep other dogs, animals or people out of the yard.
Carbon is essential for the survival, growth and reproduction of living things. It is a finite resource that comes in different forms and transfers from living to non-living things in various ways. Carbon stays balanced with other chemical reactions in the air and bodies of water through the carbon cycle.
Importance of plants. Plants have had and still have a key role in the history of life on Earth. They are responsible for the presence of oxygen, a gas needed for most organism who currently inhabit our planet and need it to breathe. But this was not always so.