( ) is taken in by plants to make food.
A: nitrogen
B: hydrogen
C: oxygen
D: carbon dioxide
A: nitrogen
B: hydrogen
C: oxygen
D: carbon dioxide
举一反三
- 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
- 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
- The synonym of CO2 is .（ ）。 A: hydrogen B: carbon monoxide C: carbon dioxide D: oxygen
- "Greenhouse gases" in Para. 2 refer to ________________. A: oxygen B: hydrogen C: carbon dioxide D: air