Hydrogen is the most _____ element in the known Universe.
举一反三
- Identify the conclusion of this sentence: (1) Hydrogen is the mose common element in the universe. (2) Since it’s so abundant, (3) cars powered by hydrogen fuel cells will eventually be so much cheaper than gasoline-powered car
- （ ）is the most abundant chemical element in plants and animals. A: Oxygen B: Carbon C: Hydrogen D: Nitrogen
- It is known that hydrogen _____ (be) the lightest element.
- The element immediately following hydrogen is helium, the atom ____ which contains two electrons.
- ] The most complex object in the universe is the human brain.