Explain why the PCR has been dubbed a "chain reaction"

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

What are the two functions of the respiratory system

When sodium chloride dissolves in water, the sodium chloride dissociates into a. na- ions. b. cl+ ions. c. nacl ions. d. sodium chloride ions.