( ) are organic compounds that are chemically based on carbon, hydrogen and other nonmetallic elements.

These renewable feed-stocks are most often associated with biological and plant based starting materials, including: A: Agricultural wastes B: Saw dust C: Carbon dioxide D: Coal

Carbon chains can rotate around a double bond (carbon=carbon or C=C).

What caused the deposits A: The hydrochloric acid broke the carbon bonds in tile carbon dioxide, B: The magnesium oxide broke the carbon oxygen bonds in the carbon dioxide. C: The burning magnesium broke the carbon oxygen bonds in the carbon dioxide. D: The gas collection method broke the carbon-oxygen bonds in the carbon dioxid

______ of agricultural practices is a recognized method of carbon sequestration as soil can act as an effective carbon sink offsetting as much as 20% of 2010 carbon dioxide emissions annually.

The synonym of CO2 is .（ ）。 A: hydrogen B: carbon monoxide C: carbon dioxide D: oxygen

Carbon dioxide consists of carbon and （ ） A: oxygen B: emergency C: upgrade D: religious

Questions 11 to 13 are based on the following talk on greenhouse gas. You now have 15 seconds to read Questions 11 to 13. Which is the most important greenhouse gas A: Methane. B: Carbon dioxide. C: Oxygen. D: Helium.

are very soft ,and can be used for bolts and for machine parts that do not need strength.: Alloy steels|High carbon steels|Low carbon steels|Medium carbon steels

carbon emission