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

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

Of the more common elements(元素) are hydrogen, oxygen, carbon, iron, copper, etc.

Carbon 14 can only determine what kind of elements of cultural relics to determine the age.( ) A: copper B: nitrogen C: oxygen D: carbon

( ) is taken in by plants to make food. A: nitrogen B: hydrogen C: oxygen D: carbon dioxide

The gas with maximum percentage in the atmosphere is ( ). A: nitrogen B: hydrogen C: oxygen D: carbon dioxide

（ ）is the most abundant chemical element in plants and animals. A: Oxygen B: Carbon C: Hydrogen D: Nitrogen

‎The atmosphere of Mars consists mostly of ______.‍ A: oxygen B: carbon dioxde C: helium D: nitrous oxide

"Greenhouse gases" in Para. 2 refer to ________________. A: oxygen B: hydrogen C: carbon dioxide D: air