Answer:
A hydrogen atom is an atom of the chemical element hydrogen.Carbon is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds.
In chemistry, an element is a pure substance consisting only of atoms that all have the same numbers of protons in their atomic nuclei.
Explanation:
I would go with B & D because they change over time and they can go extinct like those big octopus in the oceans, they are rare to see in my opinion because they can blend in with other things that keeps them away from danger.
Cells are very different but have similar properties
Answer:
Your answer is D). Like most cold-blooded animals, geckos' bodies are unable to maintain a homeostatic body temperature on their own, therefore they must bask in the sun in order to increase their body heat, and hide in the shade when it's too hot.
