Nitrogen and oxygen are ___ important ___ most living organisms cannot survive without these elements.
举一反三
- The most significant constituents of coal are . A: hydrocarbons B: sulfur C: oxygen D: nitrogen
- What are most important for a business to survive?
- （ ）is the most abundant chemical element in plants and animals. A: Oxygen B: Carbon C: Hydrogen D: Nitrogen
- People cannot survive without plants. A: Right B: Wrong C: Not mentioned
- Which is the most abundant atom (% body weight) in the human body? ( ) A: Hydrogen B: Oxygen C: Carbon D: Nitrogen