A: hydrogen
B: carbon monoxide
C: carbon dioxide
D: oxygen
举一反三
- "Greenhouse gases" in Para. 2 refer to ________________. A: oxygen B: hydrogen C: carbon dioxide D: air
- ( ) 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
- Scientists figured out that human bodies are basically made of（） A: hydrogen, carbon, nitrogen, and oxygen atoms B: water vapor, ammonia, carbon dioxide, methane and hydrogen C: biomolecules and water D: evolutionary molecules
- Carbon dioxide consists of carbon and （ ） A: oxygen B: emergency C: upgrade D: religious
内容
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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
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The main air pollutants include : particulate matter, Ground-level ozone, Nitrogen dioxide, sulfur dioxide, carbon monoxide and lead.
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Of the more common elements(元素) are hydrogen, oxygen, carbon, iron, copper, etc.
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（ ）is the most abundant chemical element in plants and animals. A: Oxygen B: Carbon C: Hydrogen D: Nitrogen
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Which elements is not one of the three most common ones in a plant? A: Carbon B: Hydrogen C: Oxygen D: Sulfur