If the choices are A.C2H6, B.C2H4, OR C.C2H2 then the answer would be B.C2H4 because each carbon atom bonds with two hydrogen atoms and one double carbon bond.
host can be considered to be an ecosystem in that it is an environment containing a diversity of entities (e.g., parasitic organisms, commensal symbionts, host immune components) that interact with each other, potentially competing for space, energy, and resources. the url code https://www.sciencedirect.com/science/article/pii/S1471492215000409
Answer:
A
Explanation:
weather it is at that moment and constantly changing
Answer: matter
Explanation: It contains 99.85% of all the matter in the solar system.