Which is a role of helpful bacteria? A)removing nutrients from soil
B)Producing oxygen
C)healing sick animals
D)preventing tooth decay

The carbon cycle is best defined as a process in which a. carbon changes from inorganic forms to organic forms and back b. carbon is changed into other elements such as oxygen or nitrogen c. carbon is continually created from the sun’s energy by plants d. carbon is consumed and regenerated from other elements such as oxygen and nitrogen